Tag Archives: CO2

Climate change is already changing the Australian landscape

from David Donaldson at the Guardian

Climate zones along the coast of southeastern Australia have already moved south by around 350km. Those fluctuations are also altering the way rural communities live.

tree guardian

I was in high school when crested pigeons started showing up at the farm where I grew up. Situated in a flat, pastoral corner of southwest Victoria, the pointy-haired birds first seemed out of place – a budding wildlife enthusiast, I’d previously only seen photos of them in the desert.

But thanks to the millennium drought – which became progressively worse from around the time I started primary school until my final year of high school – the crested pigeons had obviously decided southwest Victoria was now sufficiently dehydrated for them to take up residence. Though the drought ended several years ago, the pigeons are now a permanent fixture on the farm; I hear their distinctive whirring sound every time I go back to visit.

The same thing happened with galahs when my father was young. The pink and grey cockatoos flew in from the north during the 1965-68 drought and have never left. Other birds, such as the charismatic grey fantail, have changed their migratory behaviour in recent years as winters become milder and shorter, as have countless species right around the world.

It’s not just the wildlife that’s changing. The hotter, drier climate gradually imposing itself on southeastern Australia is forcing changes to agriculture. In southwest Victoria, this means it’s becoming harder to produce the beef and wool my father grew when I was a child. Cereal cropping, which uses less water and creates fewer jobs, is becoming more popular.

A Crested Pigeon.
A Crested Pigeon. Photograph: Ed Dunens/Flickr

Old European trees in gardens and town centres are dying in the long, waterless summers. Aquifers are becoming harder to access as runoff remains low, while decreasing autumn precipitation is leading to a shorter growing season. Frosts are becoming less common, though clear skies, which allow heat to escape at night-time, mean minimum temperatures are not increasing at the same rate as maximums.

The changes are also altering the way rural communities live. The drought in particular had a huge and traumatic effect. Livestock previously had to be shot when feed and water ran out. Many workers ended up leaving farming because it was just too hard. Tragically, the suicide rate among farmers spiked during the final years as entire livelihoods were reduced to dust. Though drought is a recurrent theme of the Australian landscape, this one was especially long and harsh – and the research suggests such phenomena will only become more common.

As the IPCC’s fifth assessment report has reiterated, climate change is not merely a beast of the future – it’s been happening for a while. Victoria’s average annual mean temperature has increased by almost 0.9°C over the past century, around the same as the rest of Australia. Although rainfall is more variable, droughts are becoming longer and drier. Record high temperatures are regularly broken, while record lows are becoming harder to find.

Climate zones along the coast of southeastern Australia have already moved south by around 350km. Those on the northeast coast have shifted around 200km. Fish species are travelling further south than before. Long-spined sea urchins, previously found only as far south as southern NSW, have been caught in eastern Tasmania. Other organisms have specific, geographically-bound ranges that do not allow them to move, and will find it difficult to adapt to warmer seas.

Terrestrial animals will increasingly face the same problem. Our national parks are poorly connected in large areas of Australia, meaning many creatures will be unable to migrate as temperatures increase. Some animals escaping monsoonal northern Australia will find it difficult to survive in drier inland areas. Alpine animals, such as the Leadbeater’s Possum, will be especially challenged as thin snowfall and bigger bushfires cause their habitat to disappear.

But while the outlook is concerning for agricultural production and downright terrible for our natural habitat, there are a few glimmers of hope. It’s reassuring that, despite the acrimony surrounding climate politics at a national level, there are plenty of community groups and governmental bodies conducting important research into how we deal with a hotter, drier Australia. While politicians and vested interests have muddied the waters of public opinion for strong action to stop climate change, pragmatism based on evidence is leading progress in adaptation and mitigation.

Though it may be politically conservative, southwest Victoria is no exception. In 2013 for example, Moyne shire released an extensive coastal hazard assessment report for popular holiday town Port Fairy, finding that several hundred buildings would be at risk of inundation by seawater as ocean levels rise.

Individual farmers, landcare groups and catchment management authorities are working on a range of projects to increase biodiversity and improve agricultural processes. Nationally, the CSIRO is breeding new types of drought-tolerant wheat that will hopefully prevent a decline in productivity as the landscape becomes drier.

We’re already seeing the effects climate change is having on the natural world. Even if governments start making a serious effort to combat climate change today, we won’t be starting from zero – the clock started long ago, but we’re still crouched at the starting block.

Sooner or later, we’ll all be touched by climate change in some way, as indeed many already have. Hopefully we’ll be prepared for it.

Original story here

 

 

 

1 Comment

Filed under Climate Change

Tony Abbott’s “Direct (in)Action” plan flawed.

Everyone knows it, even the coalition themselves. The vast majority of them are climate change deniers and their plan will actually put money in the pockets of polluters and allow them to increase emissions. Now, a Senate committee has examined the plan and given it a huge tick of disapproval.

from the Guradian

‘Flawed’ Direct Action climate plan should go, says Senate committee

Increased cuts in emissions and floating carbon price recommended to replace Coalition scheme

cooling towers

The federal government’s climate change plan is “fundamentally flawed” and should be ditched in favour of a floating price on carbon, a Senate committee report has found.

The committee report recommended the government “immediately adopt” the emissions reduction targets put forward by the independent Climate Change Authority, which the Coalition has vowed to disband.

This would deepen the cut in emissions by 2020 – from the present target of 5% – to 15% below levels in 2000. The cut would become 19% if Australia’s Kyoto Protocol commitments were factored in.

The committee also recommended the clean energy package introduced by the previous Labor government should not be repealed, including the retention of the Clean Energy Finance Corporation, which the government again moved to abolish on Thursday.

 A floating carbon price should be introduced in place of the proposed Emissions Reduction Fund, which is the centrepiece of the Coalition’s Direct Action climate plan, the committee recommended.

The fund, which will pay out $2.55bn over the next four years, is designed to help lower emissions by paying businesses and farmers to undertake projects which cut CO2 output or store carbon in soil and plants.

But the committee said the fund was “fundamentally flawed” in a number of ways.

The report states the plan does not have enough money to fund the abatement required for Australia to meet its 5% emissions cut, that there is no legislated limit on Australia’s emissions, no access to international emissions credits and no proper system around how to work out a business’ baseline emissions.

However, the committee was split along party lines, with Coalition senators John Williams and Anne Ruston dissenting from almost all the report’s findings.

 The two senators said Direct Action had to replace the carbon tax due to the high cost of the current policy in return for a questionable emissions cut.

“The government believes there is a better way to tackle climate change than by imposing a $7.6bn, economy-wide tax that hinders business and does nothing for the environment,” Williams and Ruston said in a statement.

“The Direct Action plan with the Emissions Reduction Fund as its centrepiece will provide incentives rather than penalties to reduce emissions: incentives for businesses to innovate and invest in new technologies, incentives to improve the efficiency and productivity of businesses’ operations and incentives to encourage farmers and landholders to store carbon on the land.”

The federal environment minister, Greg Hunt, has dismissed the findings of the report, noting that four of the six committee members are Labor or Greens senators.

“This was written by Labor and Greens senators – of course they’re going to be running a whitewash of their own policy,” he told ABC Radio.

Several independent studies of the Direct Action plan have raised doubts over whether it can meet the 5% reduction target without more funding, something the government has ruled out.

The Climate Institute has run an analysis that is critical of the Direct Action plan, but said that both Labor and the Coalition needed to increase their ambition over emissions cuts.

“Neither party can claim any climate credibility for their policies if they remain fixated on the minimum reduction effort required and not what is Australia’s fair share in avoiding the internationally agreed climate goal of avoiding two-degrees warming,” said John Connor, the chief executive of the Climate Institute.

“As one of the countries most exposed to climate risks it is in our national interest to establish credible targets.”

 Mark Butler, Labor’s environment spokesman, said expert advice heard by the committee showed that the Direct Action plan was deficient.

“After four years, three Senate inquiry hearings and two Senate estimates hearings, no one, not least the government or the Environment Department, can describe how Direct Action is going to achieve its goals,” he said.

“Direct Action is nothing more than a dressed-up slush fund with a pretty name.”

The Greens leader, Christine Milne, said: “The inquiry has made it crystal clear that Direct Action is not a viable replacement for carbon pricing and is vastly inferior to the existing law.”

“Direct Action is just a slogan. There was not a single economist in written submissions or testimony who supported Direct Action over the existing emissions trading scheme. Not Ross Garnaut, not Bernie Fraser, no one.”

Original article here

2 Comments

Filed under Uncategorized

It’s going to be hot…very hot

Most of us who follow climate science closely have been watching with interest the developing situation in the Pacific Ocean with the Southern Oscillation and the predictions that we are headed for an El Nino..and a big one at that. First, for anyone unaware of what I’m talking about, this short video explains things very nicely and simply.

What this video doesn’t discuss are the implications for the global climate of the Southern Oscillation and in particular what the relative strength of an El Nino does. It is hypothesised that during neutral and La Nina years, energy from the sun accumulates in the deep ocean and as the Southern  Oscillation switches to an El Nino phase, surplus energy is released at the ocean surface/air interface, raising the average surface air temperature. With the enhanced greenhouse effect caused by anthropogenic emissions of CO2 and other greenhouse gases, more of this heat is trapped and over time, the temperature goes up.

Levitus2012OHC

What becomes obvious when looking at global surface air temperature data is the difference in the highs between El Nino years, La Nina years and neutral years.

201213What this graph shows quite clearly is that in any given period El Nino years are relatively hotter than La Nina and neutral years. 1998, the year that AGW deniers like to cherrypick was an exceptional year as the preceding El Nino was an extremely strong one. An explanation for how the Southern Oscillation Index (SOI) works and what constitutes an El Nino, a La Nina and a neutral state is provided by the BOM.

Sustained positive values of the SOI above +8 may indicate a La Niña event, while sustained negative values below −8 may indicate an El Niño event. Values of between about +8 and −8 generally indicate neutral conditions.

The following graph shows the SOI for the period 1994-1997. Take note of the values for the very strong El Nino of 1997-98. The strength of that El Nino was reflected in the average global surface temperature of 1998 as mentioned previously.

soiSo, to this year. Today the BOM released its latest ENSO wrap up. They are predicting a high possibility of an El Nino developing based on the SOI.

While the tropical Pacific Ocean remains El Niño–Southern Oscillation (ENSO) neutral, the chance of an El Niño occurring in 2014 has increased. The latest climate model survey by the Bureau shows that the tropical Pacific is likely to warm in the coming months, with most models showing sea surface temperatures reaching El Niño thresholds during the southern hemisphere winter.

Observations indicate that the tropical Pacific Ocean is currently warming. Following two strong westerly wind bursts since the start of the year, waters below the surface of the tropical Pacific have warmed significantly over the past two months. This has led to some warming at the surface, with further warming expected in the coming weeks. The Southern Oscillation Index (SOI) has dropped to –13—the lowest 30-day value since March 2010—but would need to remain firmly negative for several weeks to indicate the atmosphere and ocean are reinforcing each other.

soi30

A month or so ago, researchers, using a different data set predicted an El Nino for this year giving a 76% likelihood of one developing and a big one at that. It is now being reported that US atmospheric scientists are also predicting a very large El Nino.

ABC Rural:

The sub surface temperature of the eastern Pacific Ocean is measuring an ‘astounding’ six degrees warmer than normal for this time of year.

A team of US atmospheric scientists says that points to a major El Nino event forming to rival the record event nearly 20 years ago.

El Nino is associated with dry conditions and reduced monsoons in Australia and Indonesia, but wetter weather in Central America.

Paul E. Roundy, associate professor of atmospheric science at the University at Albany, New York, says there’s been a series of westerly winds that amplify waves, moving warm currents of water thousands of kilometres and moving a surge of warm water from west to east.

That pushes the warm water to considerable depths.

“It’s close to a 70 or 80 per cent chance of a major event,” Associate Professor Roundy said.

“The Climate Prediction Centre would disagree and set the rates lower.

“But I’m thinking in the context of what we observe in the ocean right now, is consistent with that kind of major event developing.

“No guarantee! But it is consistent.

“The only time that (the six-degree warming) has ever happened before, this time of the year, was in that March of 1997 event. So it highlights the risk, even though there’s only one event like that.

Indications are that a huge Kelvin Wave has been developing and a large pool of very warm water is popping up close to South America, both indicators of a major El Nino event.

Accuweather:

This Kelvin Wave is of historic strength, clocking in at roughly +5.64º C above normal as of March 20th. It was at +5.35º C on March 13th, marking a +0.29º C change in just 7 days. Even more concerning is the push to the surface, and how the KW continues to strengthen. As we look to see westerly winds continue from the western Pacific, I have little doubt we’ll see an El Nino be declared in the next 4-10 weeks.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/weeklyenso_clim_81-10/wkd20eq2_anm.gif

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/weeklyenso_clim_81-10/wkteq_xz.gif

So, I guess time will really tell but all the indicators are pointing to a large El Nino this year and we are probably due for one anyway. If I was living in southeastern Australia in a bushfire prone area, I’d be thinking about planning for the worst. As for our farmers, I’m not sure what they can do about the likely super-drought conditions that will result from the El Nino overlaid on the already long-term diminishing rainfall conditions experienced across most of southern Australia.

Refs:

http://mobile.abc.net.au/news/2014-03-24/strong-el-nino/5340708

http://www.bom.gov.au/climate/enso/

http://www.bom.gov.au/climate/current/soihtm1.shtml

http://forums.accuweather.com/index.php?showtopic=31585&st=20&start=20

http://www.bom.gov.au/watl/about-weather-and-climate/australian-climate-influences.shtml?bookmark=enso

http://skepticalscience.com/levitus-2012-global-warming-heating-oceans.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5 Comments

Filed under Uncategorized

2036: a year to fear

I have added a few pictures to this story, because I fell they tend to add something to a story that is all words. The original from Scientific American came pictureless. I’m sure they won’t mind.

Earth Will Cross the Climate Danger Threshold by 2036

Michael Mann

The rate of global temperature rise may have hit a plateau, but a climate crisis still looms in the near future.

“Temperatures have been flat for 15 years–nobody can properly explain it,” the Wall Street Journal says. “Global warming ‘pause’ may last for 20 more years, and Arctic sea ice has already started to recover,” the Daily Mail says. Such reassuring claims about climate abound in the popular media, but they are misleading at best. Global warming continues unabated, and it remains an urgent problem.

The misunderstanding stems from data showing that during the past decade there was a slowing in the rate at which the earth’s average surface temperature had been increasing. The event is commonly referred to as “the pause,” but that is a misnomer: temperatures still rose, just not as fast as during the prior decade. The important question is, What does the short-term slowdown portend for how the world may warm in the future?

The Intergovernmental Panel on Climate Change (IPCC) is charged with answering such questions. In response to the data, the IPCC in its September 2013 report lowered one aspect of its prediction for future warming. Its forecasts, released every five to seven years, drive climate policy worldwide, so even the small change raised debate over how fast the planet is warming and how much time we have to stop it. The IPCC has not yet weighed in on the impacts of the warming or how to mitigate it, which it will do in reports that were due this March and April. Yet I have done some calculations that I think can answer those questions now: If the world keeps burning fossil fuels at the current rate, it will cross a threshold into environmental ruin by 2036. The “faux pause” could buy the planet a few extra years beyond that date to reduce greenhouse gas emissions and avoid the crossover–but only a few.

A Sensitive Debate

The dramatic nature of global warming captured world attention in 2001, when the IPCC published a graph that my co-authors and I devised, which became known as the “hockey stick.” The shaft of the stick, horizontal and sloping gently downward from left to right, indicated only modest changes in Northern Hemisphere temperature for almost 1,000 years–as far back as our data went. The upturned blade of the stick, at the right, indicated an abrupt and unprecedented rise since the mid-1800s. The graph became a lightning rod in the climate change debate, and I, as a result, reluctantly became a public figure. In its September 2013 report, the IPCC extended the stick back in time, concluding that the recent warming was likely unprecedented for at least 1,400 years.

Although the earth has experienced exceptional warming over the past century, to estimate how much more will occur we need to know how temperature will respond to the ongoing human-caused rise in atmospheric greenhouse gases, primarily carbon dioxide. Scientists call this responsiveness “equilibrium climate sensitivity” (ECS). ECS is a common measure of the heating effect of greenhouse gases. It represents the warming at the earth’s surface that is expected after the concentration of CO2 in the atmosphere doubles and the climate subsequently stabilizes (reaches equilibrium).

The preindustrial level of CO2 was about 280 parts per million (ppm), so double is roughly 560 ppm. Scientists expect this doubling to occur later this century if nations continue to burn fossil fuels as they do now–the “business as usual” scenario–instead of curtailing fossil-fuel use. The more sensitive the atmosphere is to a rise in CO2, the higher the ECS, and the faster the temperature will rise. ECS is shorthand for the amount of warming expected, given a particular fossil-fuel emissions scenario.

It is difficult to determine an exact value of ECS because warming is affected by feedback mechanisms, including clouds, ice and other factors. Different modeling groups come to different conclusions on what the precise effects of these feedbacks may be. Clouds could be the most significant. They can have both a cooling effect, by blocking out incoming sunlight, and a warming effect, by absorbing some of the heat energy that the earth sends out toward space. Which of these effects dominates depends on the type, distribution and altitude of the clouds–difficult for climate models to predict. Other feedback factors relate to how much water vapor there will be in a warmer atmosphere and how fast sea ice and continental ice sheets will melt.

Because the nature of these feedback factors is uncertain, the IPCC provides a range for ECS, rather than a single number. In the September report–the IPCC’s fifth major assessment–the panel settled on a range of 1.5 to 4.5 degrees Celsius (roughly three to eight degrees Fahrenheit). The IPCC had lowered the bottom end of the range, down from the two degrees C it had set in its Fourth Assessment Report, issued in 2007. The IPCC based the lowered bound on one narrow line of evidence: the slowing of surface warming during the past decade–yes, the faux pause.

Many climate scientists–myself included–think that a single decade is too brief to accurately measure global warming and that the IPCC was unduly influenced by this one, short-term number. Furthermore, other explanations for the speed bump do not contradict the preponderance of evidence that suggests that temperatures will continue to rise. For example, the accumulated effect of volcanic eruptions during the past decade, including the Icelandic volcano with the impossible name, Eyjafjallajökull, may have had a greater cooling effect on the earth’s surface than has been accounted for in most climate model simulations. There was also a slight but measurable decrease in the sun’s output that was not taken into account in the IPCC’s simulations.

Natural variability in the amount of heat the oceans absorb may have played a role. In the latter half of the decade, La Niña conditions persisted in the eastern and central tropical Pacific, keeping global surface temperatures about 0.1 degree C colder than average–a small effect compared with long-term global warming but a substantial one over a decade. Finally, one recent study suggests that incomplete sampling of Arctic temperatures led to underestimation of how much the globe actually warmed.

New data from Cowtan & Way taking into account Arctic temperatures reveal the pause isn’t really a pause.

None of these plausible explanations would imply that climate is less sensitive to greenhouse gases. Other measurements also do not support the IPCC’s revised lower bound of 1.5 degrees C. When all the forms of evidence are combined, they point to a most likely value for ECS that is close to three degrees C. And as it turns out, the climate models the IPCC actually used in its Fifth Assessment Report imply an even higher value of 3.2 degrees C. The IPCC’s lower bound for ECS, in other words, probably does not have much significance for future world climate–and neither does the faux pause.

For argument’s sake, however, let us take the pause at face value. What would it mean if the actual ECS were half a degree lower than previously thought? Would it change the risks presented by business-as-usual fossil-fuel burning? How quickly would the earth cross the critical threshold?

A Date with Destiny: 2036

Most scientists concur that two degrees C of warming above the temperature during preindustrial time would harm all sectors of civilization–food, water, health, land, national security, energy and economic prosperity. ECS is a guide to when that will happen if we continue emitting CO2 at our business-as-usual pace.

I recently calculated hypothetical future temperatures by plugging different ECS values into a so-called energy balance model, which scientists use to investigate possible climate scenarios. The computer model determines how the average surface temperature responds to changing natural factors, such as volcanoes and the sun, and human factors–greenhouse gases, aerosol pollutants, and so on. (Although climate models have critics, they reflect our best ability to describe how the climate system works, based on physics, chemistry and biology. And they have a proved track record: for example, the actual warming in recent years was accurately predicted by the models decades ago.)

I then instructed the model to project forward under the assumption of business-as-usual greenhouse gas emissions. I ran the model again and again, for ECS values ranging from the IPCC’s lower bound (1.5 degrees C) to its upper bound (4.5 degrees C). The curves for an ECS of 2.5 degrees and three degrees C fit the instrument readings most closely. The curves for a substantially lower (1.5 degrees C) and higher (4.5 degrees C) ECS did not fit the recent instrumental record at all, reinforcing the notion that they are not realistic.

To my wonder, I found that for an ECS of three degrees C, our planet would cross the dangerous warming threshold of two degrees C in 2036, only 22 years from now. When I considered the lower ECS value of 2.5 degrees C, the world would cross the threshold in 2046, just 10 years later [see graph on pages 78 and 79].

So even if we accept a lower ECS value, it hardly signals the end of global warming or even a pause. Instead it simply buys us a little bit of time–potentially valuable time–to prevent our planet from crossing the threshold.

Cautious Optimism

These findings have implications for what we all must do to prevent disaster. An ECS of three degrees C means that if we are to limit global warming to below two degrees C forever, we need to keep CO2 concentrations far below twice preindustrial levels, closer to 450 ppm. Ironically, if the world burns significantly less coal, that would lessen CO2 emissions but also reduce aerosols in the atmosphere that block the sun (such as sulfate particulates), so we would have to limit CO2 to below roughly 405 ppm.

We are well on our way to surpassing these limits. In 2013 atmospheric CO2 briefly reached 400 ppm for the first time in recorded history–and perhaps for the first time in millions of years, according to geologic evidence. To avoid breaching the 405-ppm threshold, fossil-fuel burning would essentially have to cease immediately. To avoid the 450-ppm threshold, global carbon emissions could rise only for a few more years and then would have to ramp down by several percent a year. That is a tall task. If the ECS is indeed 2.5 degrees C, it will make that goal a bit easier.

Even so, there is considerable reason for concern. The conclusion that limiting CO2 below 450 ppm will prevent warming beyond two degrees C is based on a conservative definition of climate sensitivity that considers only the so-called fast feedbacks in the climate system, such as changes in clouds, water vapor and melting sea ice. Some climate scientists, including James E. Hansen, former head of the nasa Goddard Institute for Space Studies, say we must also consider slower feedbacks such as changes in the continental ice sheets. When these are taken into account, Hansen and others maintain, we need to get back down to the lower level of CO2 that existed during the mid-20th century–about 350 ppm. That would require widespread deployment of expensive “air capture” technology that actively removes CO2 from the atmosphere.

Furthermore, the notion that two degrees C of warming is a “safe” limit is subjective. It is based on when most of the globe will be exposed to potentially irreversible climate changes. Yet destructive change has already arrived in some regions. In the Arctic, loss of sea ice and thawing permafrost are wreaking havoc on indigenous peoples and ecosystems. In low-lying island nations, land and freshwater are disappearing because of rising sea levels and erosion. For these regions, current warming, and the further warming (at least 0.5 degree C) guaranteed by CO2 already emitted, constitutes damaging climate change today.

Let us hope that a lower climate sensitivity of 2.5 degrees C turns out to be correct. If so, it offers cautious optimism. It provides encouragement that we can avert irreparable harm to our planet. That is, if–and only if–we accept the urgency of making a transition away from our reliance on fossil fuels for energy.

Original article here

 

8 Comments

Filed under Uncategorized

A remarkably accurate global warming prediction, made in 1972

I don’t know about my readers, but I am sick to the back teeth with uneducated idiots sitting at their computers typing bullshit feelpinions about their (I’m being generous) perception of climate science, using the argument that because the science is imprecise, nothing should be done to reduce carbon emissions.  Like other concern trolls, they try to give the impression of reasonableness, but are they? Is it reasonable to reject a consensus of 97% of experts that are 95% certain there is a serious problem, while insuring their houses and vehicles against accidents that only have a 1% or less chance of occurring, according to experts? It’s a bizarre position to take especially when the consequences of taking no action against climate change are far more serious. It’s idiotic.

But to the notion that climate systems are poorly understood and the predictions inaccurate. Dana Nuccitelli writing for the Guardian discusses a 1972 Nature paper from John Stanley Sawyer which has proven remarkably accurate.

 

John Stanley (J.S.) Sawyer was a British meteorologist born in 1916. He was elected a Fellow of the Royal Society in 1962, and was also a Fellow of the Meteorological Society and the organization’s president from 1963 to 1965.

A paper authored by Sawyer and published in the journal Nature in 1972 reveals how much climate scientists knew about the fundamental workings of the global climate over 40 years ago. For example, Sawyer predicted how much average global surface temperatures would warm by the year 2000.

The increase of 25% CO2 expected by the end of the century therefore corresponds to an increase of 0.6°C in the world temperature – an amount somewhat greater than the climatic variation of recent centuries.

Remarkably, between the years 1850 and 2000, atmospheric carbon dioxide levels did increase by very close to 25 percent, and global average surface temperatures also increased by just about 0.6°C during that time.

Sawyer also discussed several other important aspects of the Earth’s climate in his paper. For example, he addressed the myth and misunderstanding that as a trace gas in the atmosphere, it may seem natural to assume that rising levels of carbon dioxide don’t have much impact on the climate. Sawyer wrote,

Nevertheless, there are certain minor constituents of the atmosphere which have a particularly significant effect in determining the world climate. They do this by their influence on the transmission of heat through the atmosphere by radiation. Carbon dioxide, water vapour and ozone all play such a role, and the quantities of these substances are not so much greater than the products of human endeavour that the possibilities of man-made influences may be dismissed out of hand.

Sawyer referenced work by Guy Callendar in the late 1930s and early 1940s, in which Callendar estimated that the amount of carbon dioxide in the atmosphere had increased by about 10 percent over the prior 100 years (an impressively accurate measurement, as current estimates put the increase during that time at about 9 percent). Sawyer also referenced the Keeling Curve, which included continuous reliable measurements of the amount of carbon dioxide in the atmosphere beginning in 1958.

Compared to measurements of human carbon dioxide emissions from burning fossil fuels, Sawyer noted that only about half of those human emissions were remaining in the atmosphere. The other half, climate scientists had concluded, were being absorbed by the oceans and the biosphere. Sawyer wrote,

Industrial development has recently been proceeding at an increasing rate so that the output of man-made carbon dioxide has been increasing more or less exponentially. So long as the carbon dioxide output continues to increase exponentially, it is reasonable to assume that about the same proportion as at present (about half) will remain in the atmosphere and about the same amount will go into the other reservoirs.

Indeed, over the past four decades, human carbon dioxide emissions have continued to increase more or less exponentially, and about half has continued to remain in the atmosphere with the other half accumulating in natural reservoirs. The carbon dioxide being absorbed by the oceans has contributed to the problem of ocean acidification, sometimes referred to as “global warming’s evil twin.”

Climate scientists also had a good idea how quickly carbon dioxide levels in the atmosphere would continue to rise as a result of human activities.

Bolin has estimated that the concentration of carbon dioxide will be about 400 ppm by the year 2000. A recent conference put the figure somewhat lower (375 ppm).”

The latter prediction at the referenced 1971 conference on “the Study of Man’s Impact on Climate” turned out to be quite accurate. In 2000, atmospheric carbon dioxide concentrations were measured at about 370 ppm.

In his paper Sawyer discussed the predicted impacts resulting from a continued rise in atmospheric carbon dioxide. He noted that directly “it might make some vegetation grow a little faster,” which is generally true, although the situation is complicated. Sawyer noted that rising carbon dioxide levels would cause an increased greenhouse effect, and the associated warming would lead to more evaporation and more water vapor in the atmosphere. As a greenhouse gas itself, that rise in water vapor would act to further amplify human-caused global warming.

…if world temperatures rise due to an increase in carbon dioxide, it is almost certain that there will be more evaporation of water–the water vapour content of the atmosphere will also increase and will have its own effect on the radiation balance.

Sawyer referenced a 1967 paper by Manabe and Wetherald, who had calculated that a doubling of atmospheric carbon dioxide would by itself cause approximately 1.3°C global surface warming, but that warming would be amplified by a further 1.1°C due to rising water vapor concentrations if the relative humidity were to remain constant. Observations have indeed unequivocally shown that water vapor strongly amplifies human-caused global warming, for example as found in a 2009 study by Andrew Dessler and Sun Wong from Texas A&M University.

Sawyer also discussed that melting ice and snow in a warming world would act to amplify global warming, but suggested that increasing cloud cover might dampen global warming and act to regulate the global climate. However, recent research has shown that clouds may actually weakly amplify global warming as well. Sawyer also understood that significant global warming would cause changes in weather and wind patterns around the world.

All in all, Sawyer’s 1972 paper demonstrated a solid understanding of the fundamental workings of the global climate, and included a remarkably accurate prediction of global warming over the next 30 years. Sawyer’s paper was followed by similarly accurate global warming predictions by Wallace Broecker in 1975 and James Hansen in 1981.

This research illustrates that climate scientists have understood the main climate control knobs for over four decades. Perhaps it’s about time that we start listening to them.

Here’s to that. Original article here.

3 Comments

Filed under AGW comments, Climate Change, denier contradictions

Four climate change facts to keep the US Senate up all night

This was written inlight of the US Senate sitting to discuss climate action but these fourclimate facts certainly keep me awake.

Four climate change facts to keep the US Senate up all night.

Comments Off

Filed under Uncategorized

Australian Coal Industry CO2 policy – filling the gap.

Nothing to say here…just watch.

 

2 Comments

Filed under Uncategorized

climate change – evidence and causes

I feel that every now and then it is good to get back to the basics of climate change science andlook at the big picture. The Royal Society in conjunction with the US National Academy of Sciences have released a primer in a straight forward Q and A style, presenting the evidence for and causes of climate change. It is written in a style that even the simplest of deniers should be able to understand….. maybe.

Climate Change – Evidence and Causes

Comments Off

Filed under Uncategorized

China’s Plan to Clean Up Air in Cities Will Doom the Climate, Scientists Say

Coal-to-gas projects in rural areas could double carbon footprint of fuel burned in cities, spelling disaster for earth’s climate, warn scientists.

By William J. Kelly, InsideClimate News

China is erecting huge industrial complexes in remote areas to convert coal to synthetic fuel that could make the air in its megacities cleaner. But the complexes use so much energy that the carbon footprint of the fuel is almost double that of conventional coal and oil, spelling disaster for earth’s climate, a growing chorus of scientists is warning.

Read the full story and be prepared to get angry at the pictures here

 

1 Comment

Filed under Climate Change, Rogue's Gallery

An extinction in the blink of an eye – CO2 implicated

MIT researchers find that the end-Permian extinction happened in 60,000 years — much faster than earlier estimates.

Jennifer Chu, MIT News Office

The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 percent of marine species and 70 percent of life on land — including the largest insects known to have inhabited the Earth. Multiple theories have aimed to explain the cause of what’s now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted. The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 percent of marine species and 70 percent of life on land — including the largest insects known to have inhabited the Earth. Multiple theories have aimed to explain the cause of what’s now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.

endpermianNow researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years — practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.

“We’ve got the extinction nailed in absolute time and duration,” says Sam Bowring, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. “How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation.”

In addition to establishing the extinction’s duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, , the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere. This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life.

But what originally triggered the spike in carbon dioxide? The leading theory among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma. To determine whether eruptions from the Siberian Traps triggered a massive increase in oceanic carbon dioxide, Burgess and Bowring are using similar dating techniques to establish a timescale for the Permian period’s volcanic eruptions that are estimated to have covered over five million cubic kilometers.

“It is clear that whatever triggered extinction must have acted very quickly,” says Burgess, the lead author of a paper that reports the results in this week’s Proceedings of the National Academy of Sciences, “fast enough to destabilize the biosphere before the majority of plant and animal life had time to adapt in an effort to survive.”

Pinning dates on an extinction

In 2006, Bowring and his students made a trip to Meishan, China, a region whose rock formations bear evidence of the end-Permian extinction; geochronologists and paleontologists have flocked to the area to look for clues in its layers of sedimentary rock. In particular, scientists have focused on a section of rock that is thought to delineate the end of the Permian, and the beginning of the Triassic, based on evidence such as the number of fossils found in surrounding rock layers.

Bowring sampled rocks from this area, as well as from nearby alternating layers of volcanic ash beds and fossil-bearing rocks. After analyzing the rocks in the lab, his team reported in 2011 that the end-Permian likely lasted less than 200,000 years. However, this timeframe still wasn’t precise enough to draw any conclusions about what caused the extinction.

Now, the team has revised its estimates using more accurate dating techniques based on a better understanding of uncertainties in timescale measurements.

With this knowledge, Bowring and his colleagues reanalyzed rock samples collected from five volcanic ash beds at the Permian-Triassic boundary. The researchers pulverized rocks and separated out tiny zircon crystals containing a mix of uranium and lead. They then isolated uranium from lead, and measured the ratios of both isotopes to determine the age of each rock sample.

From their measurements, the researchers determined a much more precise “age model” for the end-Permian extinction, which now appears to have lasted about 60,000 years — with an uncertainty of 48,000 years — and was immediately preceded by a sharp increase in carbon dioxide in the oceans.

‘Spiraling toward the truth’

The new timeline adds weight to the theory that the extinction was triggered by massive volcanic eruptions from the Siberian Traps that released volatile chemicals, including carbon dioxide, into the atmosphere and oceans. With such a short extinction timeline, Bowring says it is possible that a single, catastrophic pulse of magmatic activity triggered an almost instantaneous collapse of all global ecosystems.

Andrew Knoll, a professor of earth and planetary sciences at Harvard University, says the group’s refined timeline will give scientists an opportunity to test whether the timing of the Siberian Traps eruptions coincides with the extinction.

“Most mechanisms proposed to account for the observed pattern of extinction rely on rapid environmental change, so the sharp constraints on timing also serve as tests of these ideas,” Knoll says.  “[This new timeline] bring us closer to the resolution of a major problem posed by the geologic record.”

To confirm whether the Siberian Traps are indeed the extinction’s smoking gun, Burgess and Bowring plan to determine an equally precise timeline for the Siberian Traps eruptions, and will compare it to the new extinction timeline to see where the two events overlap. The researchers will investigate additional areas in China to see if the duration of the extinction can be even more precisely determined.

“We’ve refined our approach, and now we have higher accuracy and precision,” Bowring says. “You can think of it as slowly spiraling in toward the truth.”

Now researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years — practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.

“We’ve got the extinction nailed in absolute time and duration,” says Sam Bowring, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. “How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation.”

In addition to establishing the extinction’s duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, , the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere. This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life.

But what originally triggered the spike in carbon dioxide? The leading theory among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma. To determine whether eruptions from the Siberian Traps triggered a massive increase in oceanic carbon dioxide, Burgess and Bowring are using similar dating techniques to establish a timescale for the Permian period’s volcanic eruptions that are estimated to have covered over five million cubic kilometers.

“It is clear that whatever triggered extinction must have acted very quickly,” says Burgess, the lead author of a paper that reports the results in this week’s Proceedings of the National Academy of Sciences, “fast enough to destabilize the biosphere before the majority of plant and animal life had time to adapt in an effort to survive.”

Significance

PNAS reports the significance of this paper as: Mass extinctions are major drivers of macroevolutionary change and mark fundamental transitions in the history of life, yet the feedbacks between environmental perturbation and biological response, which occur on submillennial timescales, are poorly understood. We present a high-precision age model for the end-Permian mass extinction, which was the most severe loss of marine and terrestrial biota in the last 542 My, that allows exploration of the sequence of events at millennial to decamillenial timescales 252 Mya. This record is critical for a better understanding of the punctuated nature and duration of the extinction, the reorganization of the carbon cycle, and a refined evaluation of potential trigger and kill mechanisms

Abstract

The end-Permian mass extinction was the most severe loss of marine and terrestrial biota in the last 542 My. Understanding its cause and the controls on extinction/recovery dynamics depends on an accurate and precise age model. U-Pb zircon dates for five volcanic ash beds from the Global Stratotype Section and Point for the Permian-Triassic boundary at Meishan, China, define an age model for the extinction and allow exploration of the links between global environmental perturbation, carbon cycle disruption, mass extinction, and recovery at millennial timescales. The extinction occurred between 251.941 ± 0.037 and 251.880 ± 0.031 Mya, an interval of 60 ± 48 ka. Onset of a major reorganization of the carbon cycle immediately precedes the initiation of extinction and is punctuated by a sharp (3‰), short-lived negative spike in the isotopic composition of carbonate carbon. Carbon cycle volatility persists for ∼500 ka before a return to near preextinction values. Decamillenial to millennial level resolution of the mass extinction and its aftermath will permit a refined evaluation of the relative roles of rate-dependent processes contributing to the extinction, allowing insight into postextinction ecosystem expansion, and establish an accurate time point for evaluating the plausibility of trigger and kill mechanisms.

Citation

High Precision Time Line For Earth’s most severe Extinction by Seth D. Burgessa,Samuel Bowringa, and Shu-zhong Shenb published in Proceedings of the National Academy of Sciences doi: 10.1073/pnas.1317692111

Read abstract and get the paper here.

3 Comments

Filed under Uncategorized

Follow

Get every new post delivered to your Inbox.

Join 201 other followers