Tag Archives: Climate Change

Emissions pathway to return global warming beneath 1 degree Celsius

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Leading climate scientist Bill Hare has published the first emissions pathway to date that brings expected global warming beneath 1°C, albeit after peaking beneath 2°C and on the scale of centuries.

This is an immensely significant research topic for coral reefs as a rise in mean global temperature of 1°C appears to be the highest target that should be set if coral reefs are to be protected from serious degradation (see previous Climate Shifts post here).

Figure 2-1 depicts the global emissions pathway that Hare (2009: 25) suggests “is plausible technically” and “goes beyond the technically and economically feasible pathways published elsewhere”. It requires getting fossil CO2 emissions down to close to zero in 2050 and being carbon negative thereafter – a commitment to action that spans centuries.

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Hare (2009: 27) suggests that under this emissions pathway “global temperatures should peak below 2 degrees Celsius around mid-century and begin a slow decline, dropping to present levels by the last half of the twenty-third century.”

The means of achieving such an emissions pathway, including being carbon negative after 2050, are discussed by Hare and other authors in subsequent chapters of the Worldwatch Institute publication, ‘State of the World 2009‘. This report is peer reviewed, but Hare will hopefully publish his new modelling in a peer reviewed climate journal shortly to improve its acceptance in the scientific community.

Hare (2009: 25) acknowledges that achieving negative CO2 emissions on a global scale will be extremely difficult and “evaluation of the implications of the technologies required to achieve this are only just beginning.”

Hare’s emissions pathway builds on the recent publication by Jim Hansen and his colleagues which argued “If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that.”

The ambition of the emissions pathway suggested by Hare (2009) is far beyond any contemplated in the mainstream policy debate at present but it is likely that such radical proposals will become much more prevalent in the future.

References

Australian Climate Statement 2008

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The Australian Bureau of Meterology released the annual Australian climate statement for 2008 last week. Another warm year for Australia, 0.41°C above the standard 1961-90 average…

Overview

  • The mean annual temperature across Australia for 2008 was the 14th warmest on record (0.41°C above normal).
  • A warm year was recorded in most regions, apart from Queensland, northeast New South Wales and the Kimberley (Western Australia).
  • Above average annual rainfall was recorded across the Top End, eastern Queensland, northeast New South Wales and far west parts of Western Australia. Rainfall was average to below average in the remainder of the country.
  • Low rainfall over the southern Murray Darling Basin during 2008 further exacerbated the long dry spell in this region.

A warmer than average year
Data collected by the Bureau of Meteorology indicate that, overall, Australia’s annual mean temperature for 2008 was 0.41°C above the standard 1961-90 average, making it the nation’s 14th warmest year since comparable records began in 1910.

Most regions recorded a warm year overall, apart from Queensland, northeast New South Wales and the Kimberley. Particularly high temperatures were recorded across inland Western Australia and the Northern Territory in January, as well as western Victoria and southern South Australia in March, with a record-breaking heatwave during the first half of the month. Conversely, cool temperatures were recorded in southeast Australia during February and again in April, across most of the country in August, and across the southwest during November.

Australia’s mean temperature for 2008 was slightly lower than that recorded for the previous six years, partly due to a La Niña event that developed in late 2007 and continued into early 2008. Despite the cooling effect of La Niña, Australia has now recorded a warmer-than-average year for the past seven consecutive years. In line with the rest of the globe, Australia has experienced a background warming of about 0.9°C over the last Century. On 16 December 2008, the World Meteorological Organization (WMO) indicated that the global mean temperature was also warmer than normal during 2008 (about 0.31°C above average), making 2008 the globe’s 10th warmest year on record. It is now 23 years since the globe has experienced a cooler than average year.

Australia’s mean temperature for 2008 was slightly lower than that recorded for the previous six years, partly due to a La Niña event that developed in late 2007 and continued into early 2008. Despite the cooling effect of La Niña, Australia has now recorded a warmer-than-average year for the past seven consecutive years. In line with the rest of the globe, Australia has experienced a background warming of about 0.9°C over the last Century.

On 16 December 2008, the World Meteorological Organization (WMO) indicated that the global mean temperature was also warmer than normal during 2008 (about 0.31°C above average), making 2008 the globe’s 10th warmest year on record. It is now 23 years since the globe has experienced a cooler than average year.

Nasa climate expert makes personal appeal to Obama

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obama_hansen4The Guardian, 2nd January 2008
One of the world’s top climate scientists has written a personal new year appeal to Barack and Michelle Obama, warning of the “profound disconnect” between public policy on climate change and the magnitude of the problem.

With less than three weeks to go until Obama’s inauguration, Professor James Hansen, who heads Nasa’s Goddard Institute for Space Studies, asked the recently appointed White House science adviser Professor John Holdren to pass the missive directly to the president-elect.

In it, he praises Obama’s campaign rhetoric about “a planet in peril”, but says that how the new president acts in office will be crucial. Hansen lambasts the current international approach of setting targets through “cap and trade” schemes as not up to the task. “This approach is ineffectual and not commensurate with the climate threat. It could waste another decade, locking in disastrous consequences for our planet and humanity,” the letter from Hansen and his wife, Anniek, reads.

The letter will make uncomfortable reading for officials in 10 US states whose cap and trade mechanism – the Regional Greenhouse Gas Initiative – got under way yesterday. The scheme is the first mandatory, market-based greenhouse gas reduction programme in the US.

Hansen advocates a three-pronged attack on the climate problem.

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Did global warming stop after 1998?

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Anyone who has an interest in exploring patterns in global temperature should take a look  around WoodForTrees.org. Paul Clark, a British software developer and “practically-oriented environmentalist and conservationist” has developed an online interface that allows anyone to go examine basic longterm trends in climate time series data (including the HADCRUT3 / GISTEMP Global Temperature & HADSST2 Sea Surface Temperature, along with sunspot activity and CO2 datasets).

The interface is incredibly intuitive, and allows a variety of transformations, averaging and trend estimations within graphs. After having spent literally hours playing around on this site, I completely agree with the warnings of ‘cherry picking‘ a dataset (i.e. choosing a certain year to start the trend to exacerbate a trend). To illustrate this ‘technique’, Paul has produced this classic graph:

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Which goes to show that the temperature is either: 1) falling,  2) static, 3) rising, or 4) rising ‘really fast!’ -all depending on where you place the trendline.

As John eloquently explained in this comment a few days ago, “global warming stopped after 1998” is turning into one of the most common memes of the ‘skeptics’ and ‘deniers’. Alot of their argument relies on very heavily cherry-picked data – skeptical Science also have a great in detail discussion and counterpoint to this argument here. Contrast the above graph with the longer term view (consistent across multiple datasets), showing warming between 0.13-0.17°C/decade:

trend1

Australia aims for destruction of Great Barrier Reef

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The Australian Government has set a 2020 target of reducing direct national greenhouse gas emissions by between 5 to 15% and thereby aiming at a global scenario that would stabilise global atmospheric greenhouse gases at around 510 to 550 parts per million carbon dioxide equivalents (ppm CO2-e) by the end of the century.

Heogh-Guldberg et al (2007) illustrated what these targets mean for the Great Barrier Reef and much of the marine ecosystem in the following series of pictures. Picture A on the left represents current conditions for corals across much of the GBR. Picture C on the right represents the conditions under the atmosphere being aimed for by the Australian Government.

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The Carbon Pollution Reduction Scheme White Paper, released on 15 December 2008, does not acknowledge the expected impacts on the Great Barrier Reef if its global stabilisation targets are achieved but draws heavily on the economic analysis of Professor Ross Garnaut.

Garnaut (2008a: 38) was brutally frank in his supplementary draft report: “The [strategy of stabilising at 550 ppm CO2-e] would be expected to lead to the destruction of the Great Barrier Reef and other coral reefs.”

His final report does not shy away from this conclusion. Garnaut (2008b: 127) concluded that stabilisation at 550 ppm CO2-e will result in:

“Disappearance of reef as we know it, with high impact to reef-based tourism. Three-dimensional structure of the corals largely gone and system dominated by fleshy seaweed and soft corals.”

“A carbon dioxide concentration of 500 ppm or beyond, and likely associated temperature change, would be catastrophic for the majority of coral reefs across the planet. Under these conditions the three-dimensional structure of the Great Barrier Reef would be expected to deteriorate and would no longer be dominated by corals or many of the organisms that we recognise today.”

The White Paper all but dismisses “stabilising concentrations of greenhouse gases at around 450 parts per million or lower” because “achieving global commitment to emissions reductions of this order appears unlikely in the next commitment period [after the commitment period for the Kyoto Protocol ends in 2012].”

Note, there are significant differences in targets based on stabilising atmospheric carbon dioxide at 500 ppm (which picture C above depicts) and stabilising total radiative forcing of greenhouse gases and aerosols at 500 ppm CO2-e (see Avoiding confusion on stabilization targets for climate change and ocean acidification).

However, the White Paper appears to assume total radiative forcing will continue to roughly equal atmospheric carbon dioxide levels. Therefore, by aiming to stabilise atmospheric greenhouse gases at around 510 to 550 ppm CO2-e, the White Paper appears to be aiming to stabilise atmospheric carbon dioxide (currently around 385 ppm) at these levels.

This should sound alarm bells for anyone following the scientific literature on ocean acidification, which has found serious impacts occur to coral reefs and much of the marine ecosystem above 450-500 ppm carbon dioxide in the atmosphere (Hoegh-Guldberg et al 2007; Cao and Caldeira 2008).

The public debate in Australia has largely ignored these impacts and it remains to be seen whether there will be any real challenge to the current approach being taken by the Australian Government.

The government has been less than frank on the implications of the targets it has chosen. There is no acknowledgment of the expected impacts to the Great Barrier Reef of stabilising at 510 – 550 ppm carbon dioxide or CO2-e and the choice of stabilising in this range is obscurely buried in the body of this 800 page report.

The White Paper refers repeatedly to 2020 targets of 5-15% reductions. It also refers repeatedly to stabilising at or below 450 ppm, with Garnaut’s pessimistic conclusion that “achieving global commitment to emissions reductions of this order appears unlikely”. But a reader must connect the 5-15% reductions to one of six scenarios set out on page 4-11 of the White Paper to uncover the overall stabilisation goals.

The White Paper relies heavily on Garnaut’s findings but a reader must also connect the obscurely buried stabilisation range of 510-550 ppm in the White Paper to Garnaut’s findings in his 600 page final report.

The government appears to be silently ignoring the expected impacts to the Great Barrier Reef and seeking to avoid confrontation on these implications in selling its climate change policies to the public. Tony Jones repeatedly asked Climate Minister Penny Wong of the implications for the Great Barrier Reef of stabilising at 550 ppm in an interview on ABC Lateline on (30 November 2008). She obviously knew the answer but danced around the questions to avoid stating that the government’s targets would mean the destruction of the Great Barrier Reef.

Perhaps it is too late to save the Great Barrier Reef but silently ignoring the expected impacts when setting climate change targets is disingenuous and does not advance the public debate. We need to fully acknowledge what the science is telling us. Choosing not to listen to weather forecasts does not stop it raining.

We should judge our climate change policies by this simple test: will we leave the GBR for our children? At present the answer we are giving to this question is “no”. We are all responsible for changing the answer to “yes”.

We should demand targets based on what we as a society want to achieve. We should not accept targets that will produce unacceptable outcomes.

References:

A cooler year on a warming planet

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New York Times .earth blog |  Andrew Revkin  |  December 16, 2008 12:56 PM

NASA’s Goddard Institute for Space Studies, the World Meteorological Organization, the National Oceanic and Atmospheric Administration, and Britain’s Hadley Center have all issued recaps of the past year’s temperature patterns today.

The past year, according to the NASA group (the “meteorological year” from December through November), is between the 7th and 12th warmest (because of the range of uncertainty in readings) since systematic meteorological record-keeping began in 1880. But the Goddard scientists note that the 9 warmest years in the record have occurred since 1998…  Read the entire post here

Climate change pushes coral decline – Western Australian

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The Western Australian, 1st December 2008

The world’s marine reserves may be helping to restore local fish populations, but they are failing to protect fragile coral reefs from the harsh effects of global warming, a conference has heard.

Data collected from 8540 coral reefs in the Indian, Caribbean and Pacific regions from 1987 to 2005 show the rate of coral decline with warmer temperatures is just the same in marine reserves as in highly fished areas.

Associate Professor John Bruno from the University of North Carolina in the United States, who conducted the research, has told the Ecological Society’s annual conference the results should sound a warning bell for reef managers who believe marine reserves are more resistant to climate change.

“The biggest stresses put on coral reefs are ocean warming and disease outbreaks,” Mr Bruno told the conference at the University of Sydney on Monday.

“These stresses are regional and global in scale and local protection in marine reserves is unlikely to help these reefs resist such changes.

“Marine reserves are very important for protecting fish populations, maintaining coral reef food webs and protecting against anchor damage, but they are unlikely to reduce coral losses due to global warming,” he added.

The key to restoring and protecting coral from climate change lay in long-term regional and global strategies to combat its root causes, such as carbon dioxide emissions, Mr Bruno said.

The oceans’ acid test: can our reefs be saved? – a note from Frontiers in Ecology and the Environment

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The journal Frontiers in Ecology and the Environment have published an interesting guest editorial article titled “The oceans’ acid test: can our reefs be saved?” by Jacqueline Savitz and Ellycia Harrould-Kolieb:

The climate change dialogue has picked up steam in recent months, but it has largely ignored the oceans, in spite of the tremendous service they provide, by absorbing millions of tons of atmospheric CO2 to buffer climate change. Frontiers and other journals have highlighted the impacts of the resulting ocean acidification, but its consequences demand a lot more attention – not just for the sake of marine ecosystems, but for our own sake as well.

National Oceanic and Atmospheric Administration scientist Richard Feely aptly called ocean acidification global warming’s “evil twin”, likely because of the disturbing trend of decreased pH that has begun to occur throughout the world’s oceans. His analogy conjures up a vision of a superhero gone bad, threatening our oceans while society innocently sleeps, which is not so far off.

This “evil twin” has the power to cause a far-reaching extinction of corals, both the tropical and deepwater varieties, along with other calcifying marine organisms, which could lead to an epic disruption of ocean ecosystems in this century. The impacts on society would be widespread, ranging from commercial losses in fisheries and tourism, to lost potential for new, life-saving pharmaceuticals that could be derived from marine species. Over time, the storm protection services provided by reefs would disappear – possibly just when they’re needed most, as global warming increases storm intensity. Ripple effects will be felt throughout the marine ecosystems, as well as among seabirds and even many terrestrial species – not to mention the aesthetic loss of the vast array of intricate, ornate, colorful reef organisms that inspire awe and wonder, and which we bear an ethical responsibility to preserve for future generations.

The need to maintain the economic, ecological, and cultural services that reefs provide has led people to ask, “What will it take for governments to finally do something about it?” Let’s face it – we live on a political planet, where action is driven largely by dollars and votes, and decisions are made based on short-term, not long-term, benefits. So if we want governments to do something about ocean acidification, we need to make clear that our dollars and our votes depend on it.

According to scientists studying climate change, such as Ken Caldeira, Ove Hoegh-Guldberg, and Jim Hansen, we need to stabilize our atmospheric CO2 levels at about 350 parts per million to prevent the loss of coral reefs. To do this, the Intergovernmental Panel on Climate Change says that countries like the US need to reduce emissions by 25–40% below 1990 levels by 2020 – and another 55% reduction from 1990 levels will be required by 2050. So we are talking about the need to convert to a very low carbon economy relatively quickly. This will be no small feat. The carbon we have been pumping into the atmosphere for free until now will cost us, retroactively. And it cannot be free from here on out, if we hope to solve the problem. Nevertheless, there is a lot we can do now.

(Read more at the Ocean Acidification Blog)

Obama’s win refreshes key climate talks – Nature Special Report

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As all eyes turn to Poland for the start of the United Nations meeting next week, Jeff Tollefson (Nature Special Report) looks at what progress is likely to be made.

Nature News, 27th November 2008

The United Nations Climate Change Conference that begins in Poznań, Poland, on 1 December will in some ways mark the end of an era. The United States’ long-standing opposition to climate regulation is vanishing, offering new opportunities for cooperation with its allies in Europe and beyond.

But to some extent, international climate negotiators will remain in limbo until 20 January 2009, when US President-elect Barack Obama enters the White House. Obama has advocated forceful domestic action on global warming and re-engagement with the international community.

“There is a lot of hope and a lot of optimism,” says Rob Bradley, who heads international climate policy at the World Resources Institute, an environmental think tank in Washington DC. “A lot of countries will be willing to give the benefit of the doubt to the new administration — but they are all very aware that in Poznań they will be talking to the old administration.”

The meeting will bring together representatives from some 192 countries in an ongoing effort to craft a global-warming accord to succeed the Kyoto Protocol, which was adopted in 1997 and expires in 2012. UN officials hope to reach a successor agreement in Copenhagen next year to leave time for implementation and ratification. Yet many think that goal is too ambitious, especially at a time when world leaders are worried about the global economy.

Poland has cited economic reasons in trying to build a coalition to block a European Union rule that, among other things, would require full auctioning of carbon allowances in 2013. But Saleemul Huq, of the International Institute for Environment and Development in London, thinks that opposition is now waning. He says the European Council might even move ahead with the rule as early as 12 December, the last day of the Poznań conference. The US re-engagement will only help, he says. “People will have a more rosy outlook in terms of being able to achieve something,” says Huq, “and that will probably bend the European position in a more positive direction.”

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Appreciating the immense timescales of climate change and ocean acidification

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While the present policy debate on climate change focuses on 2020, 2050 and 2100 targets, our present use of fossil fuels will continue to affect the atmosphere and the oceans for many, many thousands of years.

David Archer and Victor Brovkin (2008: 292) point out, “the notion that global warming will last only a few centuries is widespread in the popular and even in the scientific literature on climate change. This misconception may have its roots in an oversimplification of the carbon cycle.”

The IPCC (2007: 515) illustrated the carbon cycle in the 1990s in the following diagram of carbon reservoirs and main annual fluxes (pre-industrial ‘natural’ fluxes in black and anthropogenic fluxes in red):

[Note: Reservoir and main annual fluxes are in Gigatonnes of carbon. These may be converted to CO2 figures by multiplying by 44/12].

In a significant revision of its earlier reports, the IPCC (2007) concluded that natural processes in the carbon cycle will be slow to remove the current levels of CO2 from the atmosphere. Following perturbation of the natural Carbon Cycle about 50% of an increase in atmospheric CO2 will be removed within 30 years, a further 30% will be removed within a few centuries and the remaining 20% may remain in the atmosphere for many thousands of years (IPCC 2007: 514).

Archer and Brovkin (2008) reviewed long-term carbon cycle models from the recently published literature. They noted, “carbon cycle models respond to a release of new CO2 into the atmosphere in a series of several well-defined stages lasting for many millennia.” In the first stage, fossil fuel CO2 released into the atmosphere equilibrates with the ocean, which takes centuries or a millennium due to the slow overturning circulation of the ocean.

Archer and Brovkin (2008: 284) noted that the lifetime of individual CO2 molecules released into the atmosphere may only be a few years because of the copious exchange of carbon with the ocean and the land surface. However, the CO2 concentration in the air remains higher than it would have been, because of the larger inventory of CO2 in the atmosphere/ocean/land carbon cycle.

That is, the equilibrium processes removing fossil fuel CO2 emissions from the atmosphere operate at a system-wide level and individual CO2 molecules do not last for millennia in the atmosphere. Thus today’s fossil fuel CO2 emissions will not be “in” the atmosphere (literally) for a long period but they will continue to “affect” the atmosphere, the climate, and the oceans for many thousands of years.

The equilibrium processes have a major negative side for the oceans. A consequence of the oceans acting as a “sink” for CO2 emitted from burning fossil fuels is ocean acidification, discussed in several recent posts here.

Archer and Brovkin (2008: 288) point out, “after the invasion of fossil fuel CO2 into the ocean, the acidity from the CO2 provokes the dissolution of CaCO3 from the sea floor. … In the models it takes thousands of years for this imbalance to restore the pH of the ocean to a natural value.”

After fossil fuel CO2 in the atmosphere equilibrates with the oceans, atmospheric CO2 will still remain about 20-25% higher than pre-industrial levels. Archer and Brovkin (2008: 287) note that, “eventually, the excess CO2 will be consumed by chemical reactions with CaCO3 and igneous rocks, but this takes thousands of years.”

In an earlier publication, Archer (2005) found that the immense longevity of the tail on the lifetime of CO2 released into the atmosphere means 7% released by burning fossil fuels today will still be affecting the atmosphere in 100,000 years, and the mean lifetime of CO2 in the atmosphere is 30,000-35,000 years. He suggested an appropriate approximation of the lifetime of CO2 released by the burning of fossil fuels for public discussion is “300 years, plus 25% that lasts forever”.

We commonly think of our children and grandchildren to appreciate the consequences of our present actions but as our present emissions of fossil fuel will continue to affect the atmosphere for over 100,000 years, we should appreciate the decisions on climate policies today will affect the next 5,000 generations of humanity and beyond.

References:

Archer D (2005), “Fate of Fossil Fuel in Geologic Time” 110 Journal of Geophysical Research C09S05, doi: 10.1029/2004/2004JC002625

Archer D and Brovkin V (2008), “The millennial atmospheric lifetime of anthropogenic CO2” Climatic Change 90:283-297 DOI 10.1007/s10584-008-9413-1, available at http://geosci.uchicago.edu/~archer/reprints/archer.2008.tail_implications.pdf

IPCC (2007), Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the IPCC (Cambridge University Press, Cambridge). References in text are to Ch 7, pp 514-515 and available at http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter7.pdf