These posts are intended to share information and ideas about climate change and hence act as an open thread. Again I do not want to spend time in comments rehashing whether human activity causes climate change.

This edition contains items, exclusively, I think, in climate science and impacts. The thread is meant to function also as a roundtable to share information and ideas.

The New Scientist carries a story about how some cereals we know today were changed by the climate as we came out of the last ice age. Researchers at the University of Sheffield, UK took seeds of precursors of modern wheat and barley found with human remains in a 23,000-year-old archaeological site in Israel. They grew these together with four wild grass species that aren’t eaten today, but were also known to grow in the region at that time, and grew them under conditions replicating levels of CO2 then and also the higher levels when farming first arose 10,000 years ago.

All the plants grew larger under the higher levels of CO2, but the relatives of wheat and barley grew twice as large and produced double the seeds. This suggests the species are especially sensitive to high levels of CO2, making them the best choice for cultivation after the last ice age.

The team plan to look at whether other food staples around the world are similarly affected by elevated CO2 levels, for example millet grown in Asia and maize in North America. They also plan to compare the effects of CO2 on legumes such as peas. Continue reading Climate clippings 83 →