Intergovernmental Panel on Climate Change releases AR5 report

IPCC AR5 Cover IPCC PRESS RELEASE — 2 November 2014

Concluding installment of the Fifth Assessment Report: Climate change threatens irreversible and dangerous impacts, but options exist to limit its effects

COPENHAGEN, Nov 2, 2014 — Human influence on the climate system is clear and growing, with impacts observed on all continents.

If left unchecked, climate change will increase the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. However, options are available to adapt to climate change and implementing stringent mitigation activities can ensure that the impacts of climate change remain within a manageable range, creating a brighter and more sustainable future.

These are among the key findings of the Synthesis Report released by the Intergovernmental Panel on Climate Change (IPCC) on Sunday.

The Synthesis Report distils and integrates the findings of the IPCC Fifth Assessment Report produced by over 800 scientists and released over the past 13 months – the most comprehensive assessment of climate change ever undertaken.

R. K. Pachauri, Chair of the IPCC

“We have the means to limit climate change,” said R. K. Pachauri, Chair of the IPCC. “The solutions are many and allow for continued economic and human development. All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change.”

The Synthesis Report confirms that climate change is being registered around the world and warming of the climate system is unequivocal. Since the 1950s many of the observed changes are unprecedented over decades to millennia.

Thomas Stocker, Co-Chair of IPCC Working Group I

“Our assessment finds that the atmosphere and oceans have warmed, the amount of snow and ice has diminished, sea levels have risen and the concentration of CO2 has increased to a level unprecedented in at least the last 800,000 years,” said Thomas Stocker, Co-Chair of IPCC Working Group I.

The report expresses with greater certainty than in previous assessments the fact that emissions of greenhouse gases and other anthropogenic drivers have been the dominant cause of observed warming since the mid-20thcentury.

The impacts of climate change have already been felt in recent decades on all continents and across the oceans. The more human activity disrupts the climate, the greater the risks. Continued emissions of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of widespread and profound impacts affecting all levels of society and the natural world, the report finds.

The Synthesis Report makes a clear case that many risks constitute particular challenges for the least developed countries and vulnerable communities, given their limited ability to cope. People who are socially, economically, culturally, politically, institutionally, or otherwise marginalized are especially vulnerable to climate change.

R. K. Pachauri, Chair of the IPCC

“Indeed, limiting the effects of climate change raise issues of equity, justice, and fairness and is necessary to achieve sustainable development and poverty eradication. Many of those most vulnerable to climate change have contributed and contribute little to greenhouse gas emissions,” Pachauri said.“ Addressing climate change will not be possible if individual agents advance their own interests independently; it can only be achieved through cooperative responses, including international cooperation.”

Vicente Barros, Co-Chair of IPCC Working Group II

“Adaptation can play a key role in decreasing these risks,” said Vicente Barros, Co-Chair of IPCC Working Group II. “Adaptation is so important because it can be integrated with the pursuit of development, and can help prepare for the risks to which we are already committed by past emissions and existing infrastructure.”

But adaptation alone is not enough. Substantial and sustained reductions of greenhouse gas emissions are at the core of limiting the risks of climate change. And since mitigation reduces the rate as well as the magnitude of warming, it also increases the time available for adaptation to a particular level of climate change, potentially by several decades. There are multiple mitigation pathways to achieve the substantial emissions reductions over the next few decades necessary to limit, with a greater than 66% chance, the warming to 2ºC – the goal set by governments.

However, delaying additional mitigation to 2030 will substantially increase the technological, economic, social and institutional challenges associated with limiting the warming over the 21st century to below 2ºC relative to pre-industrial levels, the report finds.

Youba Sokona, Co-Chair of IPCC Working Group III

“It is technically feasible to transition to a low-carbon economy,” said Youba Sokona, Co-Chair of IPCC Working Group III. “But what is lacking are appropriate policies and institutions. The longer we wait to take action, the more it will cost to adapt and mitigate climate change.”

The Synthesis Report finds that mitigation cost estimates vary, but that global economic growth would not be strongly affected. In business-as-usual scenarios, consumption–a proxy for economic growth–grows by 1.6 to 3 percent per year over the 21st century. Ambitious mitigation would reduce this by about 0.06 percentage points.

“Compared to the imminent risk of irreversible climate change impacts, the risks of mitigation are manageable,” said Sokona. These economic estimates of mitigation costs do not account for the benefits of reduced climate change, nor do they account for the numerous co-benefits associated with human health, livelihoods, and development.

R. K. Pachauri, Chair of the IPCC

“The scientific case for prioritizing action on climate change is clearer than ever,” Pachauri said.“ We have little time before the window of opportunity to stay within 2ºC of warming closes. To keep a good chance of staying below 2ºC, and at manageable costs, our emissions should drop by 40 to 70 percent globally between 2010 and 2050, falling to zero or below by 2100. We have that opportunity, and the choice is in our hands.”

Comprehensive assessment

The Synthesis Report, written under the leadership of IPCC Chair R.K. Pachauri, forms the capstone of the IPCC Fifth Assessment Report. The first three volumes, based on outlines approved by the IPCC’s 195 member governments in 2009, were released over the past fourteen months:

  • The Physical Science Basis in September 2013
  • Impacts, Adaptation and Vulnerability, in March 2014
  • Mitigation of Climate Change in April 2014

IPCC reports draw on the many years of work by the scientific community investigating climate change. More than 830 coordinating lead authors, lead authors and review editors from over 80 countries and covering a range of scientific, technical and socio-economic views and expertise, produced the three working group contributions, supported by over 1000 contributing authors and drawing on the insights of over 2,000 expert reviewers in a process of repeated review and revision.

The authors assessed more than 30,000 scientific papers to develop the Fifth Assessment Report. About 60 authors and editors drawn from the IPCC Bureau and from Working Group author teams have been involved in the writing of the Synthesis Report. Their work was made possible by the contributions and dedication of the Synthesis Report Technical Support Unit.

R. K. Pachauri, Chair of the IPCC

“I would like to thank the hundreds of experts from the world’s scientific community who have given freely of their time and expertise to produce the most comprehensive assessment of climate change yet undertaken,” said Pachauri. “I hope this report will serve the needs of the world’s governments and provide the scientific basis to negotiators as they work towards a new global climate agreement.”

For further information about the IPCC, including links to its reports, go to: www.ipcc.ch

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New IPCC Report Leaked: Humans Cause Global Warming, Global Warming Consequences speeding up

by Joe Romm, PhD — Special to JBS News

Originally published on Climate Progress.

Temperature change over past 11,300 years (in blue, via Science, 2013) plus projected warming over the next century on humanity’s current emissions path (in red, via recent literature, much of which is reviewed in the new IPCC report.)

Temperature change over past 11,300 years (in blue, via Science, 2013) plus projected warming over the next century on humanity’s current emissions path (in red, via recent literature, much of which is reviewed in the new IPCC report.)

The Fifth — and hopefully final — Assessment Report (AR5) from the UN Intergovernmental Panel On Climate Change (IPCC) is due next month. The leaks are already here:

Drafts seen by Reuters of the study by the UN panel of experts, due to be published next month, say it is at least 95 percent likely that human activities – chiefly the burning of fossil fuels – are the main cause of warming since the 1950s.

That is up from at least 90 percent in the last report in 2007, 66 percent in 2001, and just over 50 in 1995, steadily squeezing out the arguments by a small minority of scientists that natural variations in the climate might be to blame.

This is a doubly impressive story since, as we’ve reported, Reuters has slashed climate coverage and pressured reporters to include false balance. Leading climatologists who have seen drafts of the report confirm this story’s accuracy.

Of course, nothing in the report should be a surprise to readers of Climate Progress, since the AR5 is just a (partial) review of the scientific literature (see my 12/11 post, It’s “Extremely Likely That at Least 74% of Observed Warming Since 1950″ Was Manmade; It’s Highly Likely All of It Was). The draft AR5 confirms that natural forces played a very small role in warming since 1950, which again means that human activity is highly likely be a source of virtually all of the recent warming.

I say the AR5 is a “partial” review that is “hopefully” the last because, like every IPCC report, it is an instantly out-of-date snapshot that lowballs future warming because it continues to ignore large parts of the recent literature and omit what it can’t model. For instance, we have known for years that perhaps the single most important carbon-cycle feedback is the thawing of the northern permafrost. The IPCC’s Fifth Assessment climate models completely ignore it, thereby lowballing likely warming this century.

No doubt some in the media will continue to focus on the largely irrelevant finding that the equilibrium climate sensitivity (ECS) may be a tad lower than expected.

In terms of real world warming and its impact on humans, the ECS is a mostly theoretical and oversimplified construct — like the so-called spherical cow. The ECS tells you how much warming you would get IF we started slashing emissions asap and stabilized carbon dioxide concentrations in the air around 550 parts per million (they are currently at 400 ppm, rising over 2 ppm a year, and accelerating) — AND IF there were no slow feedbacks like the defrosting permafrost.

The climate however is not a spherical cow. Every climate scientist I’ve spoken to has said we will blow past 550 ppm if we continue to put off action. Indeed, we’re on track for well past 800 ppm. And a 2012 study found that the carbon feedback from the thawing permafrost alone will likely add 0.4°F – 1.5°F to total global warming by 2100.

So the alarming disruption in our previously stable, civilization-supporting climate depicted in the top figure is our future. On our current emissions path, the main question the ECS answers is whether 9°F warming happens closer to 2080, 2100, or 2120 — hardly a cause for any celebration. Quite the reverse. Warming beyond 7F is “incompatible with organized global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems & has a high probability of not being stable (i.e. 4°C [7F] would be an interim temperature on the way to a much higher equilibrium level,” as climate expert Kevin Anderson explains here.

Dr. Michael Mann emailed me:

The report is simply an exclamation mark on what we already knew: Climate change is real and it continues unabated, the primary cause is fossil fuel burning, and if we don’t do something to reduce carbon emissions we can expect far more dangerous and potentially irreversible impacts on us and our environment in the decades to come.

As for the seeming slowdown in global warming, that turns out to be only true if one looks narrowly at surface air temperatures, where only a small fraction of warming ends up. Arctic sea ice melt has accelerated. Disintegration of the great ice sheets of Greenland and Antarctica has sped up. The rate of sea level rise has doubled from last century.

Finally, very recent studies of the ocean, which has absorbed the vast majority of the heat, also show global warming has accelerated in the past 15 years. Sadly, the AR5 appears to have stopped considering new scientific findings before the publication of this research.

Ocean Heat Content from 0 to 300 meters (grey), 700 m (blue), and total depth (violet) from Ocean Reanalysis System 4.

Ocean Heat Content from 0 to 300 meters (grey), 700 m (blue), and total depth (violet) from Ocean Reanalysis System 4.

Reuters notes that climate scientists are “finding it harder than expected to predict the impact in specific regions in coming decades.” This regional uncertainty is not surprising but still quite alarming. Indeed, it is a key reason adaptation to climate change is so much more difficult and expensive than simply reducing greenhouse gas emissions.

After all, if you don’t know where the next super-storm or super-heatwave is going to hit, you pretty much have to prepare everywhere. As a major 2011 study by Sandia National Laboratory concluded, “It is the uncertainty associated with climate change that validates the need to act protectively and proactively.” That study found because of “climate uncertainty as it pertains to rainfall alone, the U.S. economy is at risk of losing” a trillion dollars and 7 million American jobs over the next several decades.

On this point, climatologist Kevin Trenberth e-mailed me:

“We can confidently say that the risk of drought and heat waves has gone up and the odds of a hot spot somewhere on the planet have increased but the hotspot moves around and the location is not very predictable. This year perhaps it is East Asia: China, or earlier Siberia? It has been much wetter and cooler in the US (except for SW), whereas last year the hot spot was the US. Earlier this year it was Australia (Tasmania etc) in January (southern summer). We can name spots for all summers going back quite a few years: Australia in 2009, the Russian heat wave in 2010, Texas in 2011, etc.

Similarly with risk of high rains and floods: They are occurring but the location moves.”

The point is, we know that many kinds of off-the-charts extreme weather events will get more intense, longer lasting, and more frequent — in fact, they already are. But we don’t know exactly where and when they will hit, which means adaptation requires pretty much everybody, everywhere to plan the worst-case. Just when you think the Jersey shore is very unlikely to be hit by a superstorm, along comes Sandy.

I very much doubt the IPCC’s Fifth Assessment Report will move the needle on climate action because of its inadequacies; because the media has scaled back climate coverage and let go of its best climate reporters; and because the fossil fuel funded disinformation campaign will try to exploit those first two problems to make it seem like this report gives us less to worry about, when it simply underscores what we have known for a quarter-century. Continued inaction on climate change risks the end of modern civilization as we know it.

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CO2 or Methane: Who do you Love?

by John Brian Shannon

Greenhouse gas is a catch-all term used to describe a class of gases — either naturally-occurring or man-made (anthropogenic) which have a detrimental effect on the Earth’s atmosphere. It is no longer in academic dispute that any upset to the natural atmospheric equilibrium can wreak havoc on the climate of the entire planet.

As more of these gases are added to the planet’s atmosphere they allow more of the Sun’s rays to penetrate into the air mass which surrounds our planet, instead of bouncing harmlessly back into space. Scientists refer to this process as ‘solar forcing’ whereby more heat is added to the Earth each year than can be removed by natural systems. When more heat is allowed in, more of the polar ice caps melt each summer. It’s a simple equation.

It is likely that later this century there will be no northern ice cap. The other ice cap covers the continent Antarctica which is nearly the size of the United States, and is permanently covered in ice. The ice cap in Antarctica is dissipating at an increasing rate and that is no longer in academic dispute either. Both effectively function as the air-conditioning system for planet Earth and trillions of dollars are at stake for the world farming community.

Heat and drought are the deadly enemies of food crops and both excessive heat and drought are on the increase as more solar forcing is added to Earth’s climate equation. Scientists say that in the best-case scenario — with modern technology and farming practices, that up to a 2 degree worldwide average temperature increase can be accommodated with the only disruptions being in the number of food-producer bankruptcies and higher food costs for consumers. According to scientists, it is beyond our present-day ability to compensate for any worldwide temperature increase of more than 2 degrees.

Here is a staggering number to keep in mind, it costs farmers, ag corporations, consumers and governments one-trillion-dollars per year, for each one degree of worldwide temperature increase – costs which are already starting to be passed on to consumers and taxpayers.

So, who do you love: CO2 or methane? There is no doubt all greenhouse gases contribute to global warming, but some are worse than others — which is why a significant and growing movement is afoot these days to enhance and enlarge the Montreal Protocol an international agreement which limits ozone-depleting gases — to include selected greenhouse gases such as methane and nitrous oxide.

Which makes some amount of sense, as methane causes 72 times more global warming per tonne than CO2. Nitrous oxide causes 289 times more global warming per tonne than CO2. Others are exponentially worse, such as sulfur hexafluoride which contributes 16,300 times it’s weight to our atmospheric problems. Get used to hearing the term CO2-equivalent we will be hearing a lot about that in the coming months.

The worldwide tonnage of these pollutants are much lower than the billions of tonnes of carbon dioxide added to the atmosphere each year, but at those ratios even a few million tons can do a lot of lasting damage. Also, some of these emissions can stay in the atmosphere for up to 50,000 years eating ozone the entire time.

Atmospheric lifetime and GWP relative to CO2 at different time horizon for various greenhouse gases.

Gas name

Chemical
formula

  Lifetime
(years)

Global warming potential (GWP) for given time horizon

20-yr

100-yr

500-yr

Carbon dioxide

CO2

See above

1

1

1

Methane

CH4

12

72

25

7.6

Nitrous oxide

N2O

114

289

298

153

CFC-12

CCl2F2

100

11,000

10,900

5,200

HCFC-22

CHClF2

12

5,160

1,810

549

Tetrafluoromethane

CF4

50,000

5,210

7,390

11,200

Hexafluoroethane

C2F6

10,000

8,630

12,200

18,200

Sulfur hexafluoride

SF6

3,200

16,300

22,800

32,600

Nitrogen trifluoride

NF3

740

12,300

17,200

20,700

This chart is courtesy of Wikipedia, to view it full size, click here.

More CO2 is produced by our civilization than any other gas and it is prudent to limit CO2 emissions wherever possible — and to use carbon capture and storage to mitigate anthropogenic CO2 production. But it is beginning to look like all of the other greenhouse gases are the real story — and the ones most easily reduced.

At one-trillion-dollars per one-degree-of-global-warming, it is already costing consumers and taxpayers a huge amount of money. If our civilization spent just ten percent of that mitigating all of the other greenhouse gases besides CO2, we might be starting to show our planet and each other some respect.

And then, we would then know the answer to the question; Who do you Love?

JOHN BRIAN SHANNON

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