The U.S. National Academy of Sciences and the Royal Society have published a primer of Climate Change facts. Entitled “Climate Change Causes and Facts” the booklet tries to provide a fact based summary of what scientists now know and don’t know about Clinate change.
The stated purpose of the report is:
“The Royal Society and the US National Academy of Sciences, with their similar missions to promote the use of science to benefit society and to inform critical policy debates, offer this new publication as a key reference document for decision makers, policy makers, educators, and other individuals seeking authoritative answers about the current state of climate-change science. The publication makes clear what is well established, where consensus is growing, and where there is still uncertainty.”
The report, which is easily downloadable notes in part:
“Recent estimates of the increase in global average temperature since the end of the last ice age are 4 to 5 °C (7 to 9 °F). That change occurred over a period of about 7,000 years, starting 18,000 years ago. CO2 has risen by 40% in just the past 200 years, contributing to human alteration of the planet’s energy budget that has so far warmed Earth by about 0.8 °C (1.4 °F). If the rise in CO2 continues unchecked, warming of the same magnitude as the increase out of the ice age can be expected by the end of this century or soon after. This speed of warming is more than ten times that at the end of an ice age, the fastest known natural sustained change on a global scale.”