A team of US scientists show in this week's Science that incorporating changes in land use into computer simulations of climate change leads to significantly different projections for regional climates in the year 2100.
In the first simulation to include land use changes alongside atmospheric and oceanic contributions to climate change, Johannes Feddema and colleagues show that future agricultural expansion could boost global warming in the Amazon region, but reduce it in the mid-latitudes.
In an accompanying commentary, Roger Pielke Sr. argues that the Intergovernmental Panel on Climate Change (IPCC) has not given land use due recognition as a driver of climate change. The IPCC is a panel of international scientists attempting to determine the scientific consensus on climate change.
Although the IPCC has studied the impact of land use at a global level, says Pielke Sr., its effect on regional temperatures, rainfall and plant cover has been neglected.
He says that the IPCC should consider the effects of land use as at least as important as those of greenhouse gas emissions.
In addition, Pielke Sr. encourages the IPCC to study changes in temperature and their effects at the regional as well as global level.
As Feddema and his team demonstrate in their study, changes that are critically important at a regional level may cancel each other out and remain unnoticed at a global level.
Regional analyses are particularly important, Pielke Sr. concludes, because people and ecosystems experience the effects of environmental change regionally, and not as global averages.
Science 310, 1625 (2005) [R. Pielke Sr.]
Science 310, 1674 (2005) [J. Feddema et al.]