Climate Projections Current Weather and News Anthropogenic Projections IPCC AR4 Carbon Emission Scenarios Global Temperature Projections Global Precipitation and Other Projections For Next Class: Read Ch. 14

Projected Emissions to Climate Response

Group Discussion What are some factors affecting future carbon emissions? What are other anthropogenic activities that should also be accounted for?

Factors Affecting Future Carbon Emissions As long as fossil fuels remain reasonably abundant, future carbon emissions can be approximated by three factors: Human populations Change in emissions per person Changes in efficiency of carbon use Increase in carbon emissions = increase in population x change in emissions per person x changes in efficiency of carbon use

IPCC AR4 Carbon Emission Scenarios A2 – More Divided World (High Emissions) A more divided world with independently operating and self-reliant nations, continuously increasing population, regionally oriented economic development, slower and more fragmented technological changes A1B – More Integrated World (High Emissions) A more integrated world with rapid economic growth, global population reaching 9 billion in 2050, and convergence of income and way of life, balanced emphasis on all energy sources B1 – Ecologically Friendly World (Moderate Emissions) A more integrated world and more ecologically friendly, reductions in materialism and the introduction of clear and resource efficient technologies

Projected Emissions to Climate Response IPCC AR4

IPCC AR4

IPCC AR4

Global Temperature Projections IPCC AR4

Global Temperature Projections IPCC AR4

Global Temperature Projections Global temperatures are projected to increase by 1.8 to 4.0 °C by 2100 Warming is projected to be most pronounced at higher latitudes of the Northern Hemisphere, especially north of 60 °N Greatest warming likely to occur over land Little difference in projected warming among different emission scenarios for the next 25 years

Global Precipitation Projections

Multi-Model Mean Changes by 2080-2099 IPCC AR4

Global Precipitation Projections Precipitation is projected to increase in the tropics and decrease in the sub-tropics, and increase in the middle latitudes and polar regions. Precipitation intensity is also projected to increase in most regions of the world. The number of dry days is projected to increase in much of the tropics, sub-tropics, and middle latitudes.

IPCC AR4

Multi-Model Mean Sea Ice Projections IPCC AR4

Multi-Model Mean Sea Ice Projections IPCC AR4

IPCC AR4

IPCC AR4

Summary of Climate Projections Sea ice, particularly in the arctic during July, August, and September, will continue to decline dramatically. Warm-phase of ENSO (El Niño) may become more frequent. Frequency of heat waves is likely to increase. Length of growing season is likely to increase in mid-latitudes with a corresponding decrease in the number of frost days. Continued ablation of the Greenland Icecap is likely, with a volume reduction of 20% by 2275 AD.

IPCC AR5

IPCC AR5

IPCC AR5

IPCC AR5