The Weekly Carboholic: IPCC 2007 conclusions were too conservative

Posted on March 11, 2009




The Fourth Assesment Report (AR4) of the Intergovernmental Program on Climate Change (IPCC) is a consensus report. This means that politicians and diplomats from many different nations had nearly as much authority over what was written as the scientists and economists who wrote the various documents did. While the working group documents were left more-or-less alone, the executive summaries for all three working group documents used language that was literally negotiated out between dozens of countries. If China or the U.S. didn’t like a word here or there, they could refuse to sign the document until the language was changed, and we know for a fact that they did so. And when literally everyone has to approve, you end up with a document that is as watered down as the most critical signatory wants it to be.

In addition, the nature of a large organization such as the IPCC means that it can’t react fast to recent data and scientific advances. For that reason, the various working groups that produced the actual reports didn’t look at data much beyond 2002, even though significant scientific advances occurred between then and the release of the report in 2007.

A new article published by the Earth Island Institute illustrates just how conservative the IPCC reports were with respect to the emissions of greenhouse gases (GHGs) in general, and carbon dioxide (CO2) in particular.

CO2 emissions were underestimated for two main reasons. The first and lesser of the two is that the IPCC used standard emissions scenarios that assumed that carbon intensity and efficiency would continually improve. This didn’t occur – emissions from developed nations didn’t fall as anticipated. The second reason is that economic growth in both India and China was very high and nearly entirely coal-powered. And it doesn’t help that carbon intensive governments wanted to make the effects and economic effects of climate disruption look less bad than it actually is:

There is a political and diplomatic incentive to low-ball emissions predictions becaue lower numbers make the task ahead appear less onerous.

Der Spiegel last week had an article that pointed out just how onerous the task ahead will actually be, at least as it relates to China:

[E]ven with all new coal power plants equipped with CCS, China’s CO2 emissions would increase by 80 percent by 2030….

[I]f China were to commit to reducing its carbon dioxide emissions to 2000 levels by 2030, Guan says, 40 percent of its primary energy production would have to come from renewable sources like biomass, wind and hydroelectric power.

At least one skeptic, Bjorn Lomborg, claims that the IPCC science represented the latest and greatest science available. This is incorrect. Lomborg also likes to use this erroneous claim in order to support his economic theory that addressing climate disruption now costs too much and will cost less in the future. This is also incorrect. Which makes one of the stars of climate disruption skepticism significantly less than credible.


International Climate Change Congress updates IPCC science for Copenhagen

There has been a lot of new scientific data and a number of new discoveries since the most recent IPCC report was released in 2007. The International Climate Change Congress in Copenhagen this week brings together over 2000 scientists working on climate in some way in an attempt to update the science to the latest and best knowledge. Holding the Congress in March ensures that the papers presented will be available before the next round of United Nations-brokered climate negotiations scheduled for December. Tying the Congress to the Institute of Physics ensures that the papers presented will all be available to the public shortly after the conference is over and that the science will not be forced to play second fiddle to diplomatic niceties. And holding the Congress in the same city that will host the UN in nine months ensures that this conference gets press coverage. And it’s worked thus far.

Some of the larger stories that have come out of the Congress thus far, as reported by the media, are summarized below. The gist of the Congress to date, however, is easily summerized in four words – it doesn’t look good.

The Times of London reports that the Congress’ attendees expect five to six degrees C of temperature rise over the rest of the century, not the two degrees originally anticipated by the IPCC AR4. This is largely because GHG emissions have risen at twice the worst-case IPCC scenario over the last decade.

Reuters reports that scientists presenting at the Congress have found that sea levels are rising, and are expected to rise, at double the IPCC-predicted rate, producing a meter or more of sea level rise globally, with some places seeing more due to variations in local gravity (continents exert enough gravitational pull on water to increase sea level near their shores). In addition, given how slowly the ocean reacts to temperature variations, most of that rise will not be reversable.

In a rare bit of good news, the Guardian reports that Greenland’s “tipping point” is closer to six degrees Celsius instead of the previously estimated three degrees. The tipping point is the temperature at which 100% of Greenland’s ice cap – which stores enough water to raise sea levels by an estimated six meters (nearly 20 feet) – melts. Of course, it’s good news until remember that other papers estimate that the Earth will heat up by about six degrees by 2100….

S&R will be delving into the papers coming out of the Congress in greater detail in the coming days and weeks.


International Polar Year finds significant polar warming since 1959

The International Polar Year (IPY) 2007-2008 project is a massive international research project with the goal of determining how the poles have changed since the last IPY, why, and what the future holds for the Arctic and Antarctica. The third IPY (the first was in 1882-1883, the second was in 1932-1933) compared how the poles have changed since the last major global push to understand the Earth, during the International Geophysical Year 1957-1958. Some of the results have been alarming.

According to a Bloomberg article, one West Antarctic glacier was found to be moving toward the ocean 83% faster than 15 years ago and another glacier was found to have sped up 40% since it was last monitored in the 1970s. This was expected on the Antarctic Peninsula, which has heated up the most, but the Associated Press reports that ice shelves and glaciers on the coast of West Antarctica have been affected as well. Ice shelves don’t add to sea level rise if they break apart since they’re already on water, but since they hold glaciers back from moving into the ocean too fast, if the ice shelves break up, that could mean significant additions of Antarctic water to the oceans.

There have been a number of papers released recently that showed Antarctica heating and/or losing ice mass. The research summary of the work of tens of thousands of scientists from 63 countries IPY2007-2008 support the results of those papers in general.


Less CO2 absorbed by one plankton species

A paper published in Nature Geoscience last week reports that one species of calcite-shell forming plankton is no longer absorbing carbon and creating large, thick shells. Globigerina bulloides was chosen because its found globally and has existed continuously for at least the last 50,000 years. The result is interesting – G. bulloides has lost 30-35% of its shell weight since pre-industrial times as measured from ocean sediment cores. Furthermore, these results from the Southern Ocean are similar to the reduction in calcification of other life under laboratory conditions.

The observed average shell weight for modern G. bulloides represents a 35% reduction relative to Holocene shells in the 300-355 um size range and a 30% reduction in the 355-425 um size range (Fig. 2b). These decreases in shell weights of ~30-35% are consistent with decreases in calcification rates observed in experiments with corals4 and other species of planktonic foraminifera2,25 under elevated CO2.

This matters for a number of reasons. Plankton like G. bulloides are responsible for between 23 and 53% of all CO2 pulled out of the atmosphere and then sequestered in ocean sediments. So if ocean acidification is making these plankton less efficient at pulling CO2 out of the air, then that means both more CO2 left in the air to heat it up and less food for ocean animals who eat these organisms.

More CO2 in the ocean and air means less life in the ocean, and that means more climate disruption caused by CO2.

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