Evidence

Carbon Dioxide at Mauna Loa, Hawaii

Global surface temperature

Carbon Dioxide Concentrations Ice Core Data Mauna Loa (Hawaii) Parts per million

Global Average Temperature

Thousands of years ago Temperature change ( °c) Carbon dioxide (ppmv) Temperature Change ( °c) CO 2 Concentration (Antarctic Ice Core) Current Level 1800 AD Atmospheric Carbon Dioxide Concentration and Temperature change Clear correlation Clear correlation between atmospheric between atmospheric CO2 and temperature CO2 and temperature over last 160,000 years over last 160,000 years Current level of CO2 is Current level of CO2 is outside bounds of outside bounds of natural variability natural variability Rate of change of CO2 Rate of change of CO2 is also unprecedented is also unprecedented Clear correlation Clear correlation between atmospheric between atmospheric CO2 and temperature CO2 and temperature over last 160,000 years over last 160,000 years Current level of CO2 is Current level of CO2 is outside bounds of outside bounds of natural variability natural variability Rate of change of CO2 Rate of change of CO2 is also unprecedented is also unprecedented

Thousands of years ago Temperature change ( °c) Carbon dioxide (ppmv) Temperature Change through time Compares to the present temperature Current Level Atmospheric Carbon Dioxide Concentration and Temperature change Current Level 2100 CO2 Concentration in the atmosphere (Antarctic Ice Core) If nothing is done to slow greenhouse gas emissions... CO2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to increase between 2.5 – 10.4°F If nothing is done to slow greenhouse gas emissions... CO2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to increase between 2.5 – 10.4°F

Impacts of Global Warming

Sea-Level Rise

Global warming (temperature increase) Effects of global warming on water cycle Speeds up global water cycle More extreme weather events Droughts Droughts Storms Storms Floods Floods

Health Weather-related mortality Infectious diseases Air-quality respiratory illnesses Agriculture Crop yields Irrigation demands Water Resources Changes in water supply Water quality Increased competition for water Coastal Areas Erosion of beaches Inundation of coastal lands Costs to protect coastal communities Forests Change in forest composition Shift geographic range of forests Forest health and productivity Species and Natural Areas Shift in ecological zones Loss of habitat and species Potential Climate Change Impacts Sea Level Rise Temperature Precipitation

What can we do?