The release of volatile organic compounds from Earth’s forests and smoke from wildfires 3 million years ago had a far greater impact on global warming than ancient atmospheric levels of carbon dioxide, a new Yale study finds.
The research provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change and the relevance of natural components, according to the authors. They do not address or dispute the significant role in climate change of human-generated CO2 emissions. (more…)
Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.
By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change. (more…)
