Loose ends

A few misc. links on a Friday afternoon…

Do You Trust Scientists?:

Guardian columnist George Monbiot recently did the written-word equivalent of throwing his hands up in the air over the growing chasm between actual climate science and the public’s understanding of it. One of his key points is that science has grown so specialized that scientists in different disciplines are rarely even able to fully grasp one another’s work–much less us laymen. As a result, their findings can seem so complicated that it essentially amounts to a form of gibberish to the public–and whether or not you accept their findings comes down to an issue of trust.

China says drought now affecting 50 million people:

The drought began last autumn, and is the result not only of less rainfall but also unseasonably high temperatures, the official Xinhua news agency said, citing a central government meeting on the situation.

It is affecting the provinces and regions of Guangxi, Sichuan, Guizhou and Yunnan and the municipality of Chongqing. These parts of China are known for their sugar and rubber plantations.

Some areas have received 90 percent less rainfall than they should have at this time of the year, and the drought has caused economic losses of 19 billion yuan ($2.78 billion), the report said.

More than 16 million people are having difficulty accessing safe drinking water, it added.

Senate Democrats, States Wary of Draft Climate Bill’s Pre-emption Language:

Some Democratic senators and state and local air regulators are concerned that the latest draft of a Senate climate and energy bill would unduly strip authority from U.S. EPA and states.

Details emerged earlier this week that draft legislation from Sens. John Kerry (D-Mass.), Lindsey Graham (R-S.C.) and Joe Lieberman (I-Conn.) would curb EPA’s authority to regulate greenhouse gases under the Clean Air Act and would limit states’ climate laws and regulations. But that decision is not sitting well with some Democrats.

“I don’t think it should pre-empt EPA from anything,” said Sen. Dianne Feinstein (D-Calif.), chairwoman of the subcommittee that oversees EPA’s budget.

Sen. Sheldon Whitehouse (D-R.I.) said that EPA and state pre-emption would certainly be factors he considers when deciding whether to vote for the bill. “There are a lot of states that are out on this already, and a lot depends on my perception of whether we’re undercutting their efforts and how rigorous our process is,” Whitehouse said.

An industry official who met Wednesday in a closed-door session with architects of the bill said the legislation would block EPA from requiring New Source Review and Title V operating permits from stationary sources based on their greenhouse gas emissions. The draft would also block the agency from regulating greenhouse gases as air toxics and from setting nationwide emission limits — known as National Ambient Air Quality Standards (NAAQS) — based on the emissions’ effects on climate change, that person said. Additionally, it would pre-empt state and regional cap-and-trade programs.

IPCC is right: Amazon still at risk from drought, global warming:

The Amazon forest, the largest remaining tropical forest in the world and home to enormous biological and cultural diversity, stores about 100 billion tons of carbon. In recent decades, the Amazon has become a major source of greenhouse gas emissions, as clearing forest for agriculture and cattle ranching have increased. Globally, emissions from deforestation now account for about 15% of total global emissions annually — more than all emissions from transportation worldwide — and between 2000 and 2005, 60% of the deforestation in the world happened in the Amazon.

Since the mid-1990s, scientists have observed that in dry years, particularly El Niño years, forest regions that were always too moist to burn have been catching fire, killing trees and increasing carbon emissions . Most climate change models predict that unless global greenhouse gas emissions are substantially reduced in coming years, forest in a large part of the southern and eastern Amazon risks large-scale dieback, releasing large amounts of carbon to the atmosphere and replacing the forest with savanna.

A new study lead by the World Bank [World Bank Assessment of Amazon Dieback (Jan 2010) [3.4MB PDF]], which includes experts from five international modeling groups and is independently reviewed by a blue-ribbon panel of international scientists, confirms these results. The group looked at the effects of climate change, deforestation, and fires under different global emissions trajectories and found that if fossil fuels remain predominant in the global energy matrix, and deforestation attains 20% of the Amazon biome (it’s currently at 17%), 40% of the rainforest would be lost by 2025. That means that by 2100, climate change alone would reduce the Amazon forest by two-thirds. In other words, the Amazon appears to be approaching a tipping point, after which large part of the ecosystem could collapse.

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It’s not clear how we got from here to the conclusion reported in the press and across the blogosphere that the study shows that the IPCC was wrong — but it wasn’t by using logic or science. Boston University’s recent press release titled “New study debunks myths about Amazon rain forests”, claims that Samanta et al.’s article disproves the IPCC’s affirmation that large part of the Amazon is drought sensitive. But the article does nothing of the kind.

The article does not address any of the field surveys on the effects of drought that found greatly increased tree mortality, or large-scale rainfall exclusion experiments showing the same effects, or any of the modeling results. It does not consider that what happened in a single drought year may be much less important than what could happen with increasingly frequent droughts. It does not raise the mutually reinforcing effects of climate change, reduced rainfall, deforestation and fires. It does show that one series of data from one, mid-resolution satellite sensor, didn’t detect any measurable difference in the spectral signature of Amazon trees during one drought year.

One positive that has come out of the press release’s drastic mischaracterization of Semanta et al.’s article and corresponding news coverage is the quality conversations incited about the findings in the IPCC report. I’ll conclude with a portion of a statement yesterday by 19 leading scientists [PDF] who conduct research on Amazon forests, climate, and/ or fire released, which called the BU press release “misleading and inaccurate”.

There are multiple, consistent lines of evidence from ground-based studies published in the peer-reviewed literature that Amazon forests are, indeed, very susceptible to drought stress… [and] the main conclusion of the IPCC statement – that Amazonian forests are very susceptible to reductions in rainfall – remains our best understanding of the data available at the time of the IPCC report and also today.