350 parts per million is what many scientists, climate experts, and progressive national governments are now saying is the safe upper limit for CO2 in our atmosphere.
Accelerating arctic warming and other early climate impacts have led scientists to conclude that we are already above the safe zone at our current 390ppm, and that unless we are able to rapidly return to below 350 ppm this century, we risk reaching tipping points and irreversible impacts such as the melting of the Greenland ice sheet and major methane releases from increased permafrost melt.
There are three numbers you need to really understand global warming: 75, 392, and 350.
Keeling curve: This is a plot showing the atmospheric CO2 concentration (in parts per million per volume of air, or ppmV) as measured at the Mona Loa Observatory in Hawaii. The primary trend is an increase in atmospheric CO2 since the late 1950s. Currently, atmospheric CO2 increases about 3-4 ppmV per year.The annual “saw-tooth” pattern is from seasonal changes in terrestrial biomass in the northern hemisphere. When plants grow in the spring and summer, they draw down the atmospheric CO2 concentration as the consume CO2 for photosynthesis. Despite this annual draw down by plants, global CO2 in the atmosphere continues to rise.
http://skepticalscience.comaddresses misconceptions about climate change by providing sound scientific information and explanations.
Climate change in Utah:
- Executive summary of BRAC report commissioned by former Governor Huntsman. This report evaluates the effects of climate change in Utah based on analyses of published data by a group of Utah climate scientists.
- Dr. Robert Gilles is the Utah’s State Climatologist and the Director of the Utah Climate Center. In 2012, he and coauthors published a paper stating that the proportion of winter (January-March) precipitation falling as snow has decreased by 9% over the last 50 years. The authors also find that storm frequency has decreased over this period and suggest that average storm precipitation has intensified with more of it falling as rain than snow.