Climate Feedback

Olive Heffernan

Warnings that switching to biofuels as a ‘clean’ energy source could threaten food security and increase deforestation have become increasingly stark this week.

A UN report, released last Monday concluded that, despite offering considerable benefits such as clean energy for millions and the creation of wealth and jobs in poorer countries, biofuel production also has the ability to cause real destruction.

The report warned that increasing production of liquid biofuels, such as ethanol and biodiesel, could increase the price of agricultural commodities with negative economic and social impacts, especially for the world’s poor who spend a large proportion of income on food. It also raised the issue that, where forests are cleared to make way for energy crops, GHG emissions may actually be higher overall from biofuels than from fossil fuels. The report states:

Unless new policies are enacted to protect threatened lands, secure socially acceptable land use, and steer bioenergy development in a sustainable direction overall, the environment and social damage could in some cases outweigh the benefits

Today, BBC News reports on new study by the UK based Co-op Insurance Society that reiterates some of these concerns. The CIS report warns of the potentially severe environmental impacts of increased biofuel production. According to the BBC, the study found that as much as nine per cent of the world's agricultural land could be needed to replace just 10% of the world's transport fuels. The land needed for energy crops could encroach on what little land is available for food in countries threatened by famine.

Though not the first time these concerns have been raised, the reports, in particular the UN study, represent significant efforts to investigate the pros and cons of bioenergy production. For previous discussions of these issues, see George Monbiot’s series of articles on the ills of biofuels, in particular his recent piece in The Guardian in which he argues that we need a five year freeze on biofuels if we are to save the planet

The recent boom in the bioenergy sector looks set to continue. Worldwide biofuel production fdoubled in the last five years and will double again in the next four years, says the UN report. The latest IPCC Working Group III SPM, projects that biofuel use for transport will grow to 3% of total transport energy by 2030. Growth could reach up to 5-10% of total transport energy, depending on future oil and carbon prices, improvements in car efficiency and technological advances.

In the meantime, the EU and the UK have set a target of 10% of all car fuel to come from biodiesels by 2010. At the start of the year, the EC made proposals for a new EU-wide energy policy, which includes a binding target of 10% of biofuels in petrol and diesel in all member states. The public consultation on how this could be achieved – and sustainably – is open until June 4.

Posted by Olive Heffernan on May 13, 2007
Categories: Climate Policy, In the News, Mitigation, Olive Heffernan | Permalink | Comments (1) | TrackBacks (0)

(Posted by Olive on behalf of Roger)

Even the venerable New York Times is prone to completely botching a discussion of the science of climate change. In a front page article today, the NYT reports on how the National Arbor Day Foundation has updated plant hardiness maps to reflect recent changes in climate. (A plant hardiness map presents the lowest annual temperature as a guideline to what plants will thrive in what climate zones.) The NYT misrepresents understandings of variability and trend and in the process confuse more than clarify.

The new map updates a 1990 USDA map based on 1974-1986 data, and replaces it with data from 1990-2006. In most places the range of increased average minimum temperature has moved north as can be seen from a difference map between the two time periods. The difference map, shown here, has the horizontal lines because the zones used are so broad -- 10 degrees -- that the differences are only noticeable at the margins of the zones.

The New York Times reports that these differences can all be attributed to human-caused climate change, using the case of Atlanta as an illustration:

Using data from the National Oceanic and Atmospheric Administration, the Arbor Day map indicates that many bands of the country are a full zone warmer, and a few spots are two zones warmer, than they were in 1990, when the map was last updated.

Atlanta, which was in Zone 7 in 1990, is now in Zone 8, along with the rest of northern Georgia. That means that areas in the northern half of the state where the average low temperature was zero to 10 degrees Fahrenheit are now in a zone where the average low is 10 to 20 degrees. A scientific consensus has concluded that this warming trend has largely been caused by the human production of heat-trapping gases.

Because the zones span 10 degrees (or 5 degrees in the case of the 1990 USDA map) and the largest change shown on the difference map is 2 zones (i.e., >10 degrees!, now corrected), then clearly no location has jumped 2
zones! This is just an error.

More important than this simple mistake is the claim in the NYT that the changes in temperature observed in Atlanta can be attributed to human-caused greenhouse gases. In fact, the IPCC argues that it needs 30 years of records to detect trends, much less make attribution. In fact, the IPCC report just out has reported that the U.S. southeast has actually cooled over the period of record as shown below.

The underlying issue has to do with understanding the role of human-caused climate change in the context of climate variability on long time scales.

Continue reading "Confusion on Climate Variability and Trends" »

Posted by Olive Heffernan on May 03, 2007
Categories: Climate Science, Communicating Climate Change, In the News, Roger Pielke, Jr | Permalink | Comments (35) | TrackBacks (0)