09 ClimateChange

Slide 1: 

The Global Energy Balance

Slide 2: 

The Natural Greenhouse Effect

Slide 3: 

The Enhanced Greenhouse Effect What are the major greenhouse gases?

Greenhouse gases : 

Greenhouse gases Water vapor and droplets 97%, ….of the remaining 3%.... Anthropogenic gases: CO2 50-60% (fossil fuels and fires) CFC 15-25% CH4 12-20% O3 8% N2O 5%

Slide 5: 

Monthly Mean Atmospheric CO2 Now at 380 ppm, at current rate will get up to 540-970 ppm

Changes in greenhouse gases from ice core and modern data : 

Changes in greenhouse gases from ice core and modern data

Temperature trends : 

Temperature trends 2006 was the warmest year on record (since 1850) The 11 warmest years have occurred in the last 12 yrs

Hasn’t the climate changed in the past?What’s the difference between climate and weather? : 

Hasn’t the climate changed in the past?What’s the difference between climate and weather?

Slide 9: 

Links between Temperature and Atmospheric Concentration of CO2 (From the Vostok Ice Core) http://www.aad.gov.au/asset/images/525_ul-core.jpg http://www-bprc.mps.ohio-state.edu/Icecore/images/kili-drill-small.JPG

Slide 10: 

Simulated Annual GlobalMean Surface Temperature Computer simulation models show that present warming far exceeds natural variation.

IPCC : 

IPCC Intergovernmental Panel on Climate Change Latest report: http://www.ipcc.ch/SPM2feb07.pdf 2500 scientific expert reviewers 800 contributing authors from 130 countries 6 years of work "We can be very confident that the net effect of human activity since 1750 has been one of warming,“ In 2001, it said that it was "likely" that human activities lay behind the warming trends "likely" in IPCC terminology means 66% - 90% probability. Now, the panel concluded that it was at least 90% certain that human emissions of greenhouse gases rather than natural variations are warming the planet's surface.

What do sea levels and snowpack show? : 

What do sea levels and snowpack show?

What is the forecast? : 

What is the forecast? The most recent projections (IPCC): Rise of 1.8-4.5 C (3.2-7.2F) by 2100 Sea levels most likely to rise 28-43 cm

What is the prediction for rainfall? : 

What is the prediction for rainfall? Trends: wetter at high latitudes, drier at low latitudes

Slide 17: 

Sea Level Changes Sea level rise predicted to be 28-43 cm cm by 2100. Due to melting of glaciers and sea ice, but more importantly, due to thermal expansion of the ocean. Much of the human population lives near the coast. Figure 22.25

Changes to the oceanic conveyor belt : 

Changes to the oceanic conveyor belt Keeps temperatures in Europe 5-10 C warmer Melting of Arctic ice could slow circulation Result in a cooling of Europe

Slide 19: 

Expected Increases in Extreme Events Mean Climate Variable Frequency Extreme Events As the mean increases, current “extreme” events will become more common

For example, more intense hurricanes… : 

For example, more intense hurricanes… Epsilon was the 26th named storm of the busiest hurricane season on record in 2004.

Slide 21: 

Ecological Consequences of Warmer Temperatures

Slide 22: 

Changes in Malaria Riskwith 1.16oC Increase in Temperature Health Consequences of Warmer Temperatures

Collapse of the Larson B iceshelf : 

Collapse of the Larson B iceshelf From about Jan. 31 to Mar. 5, 2002 the "Larsen B" Ice Shelf collapsed and splintered into a plume of drifting icebergs. 650 feet (198.1 m) thick surface area of 1,250 square miles, (3237 km) or about the size of Rhode Island.

Slide 24: 

Ecological Consequences of Warmer Temperatures Figure 22.26 Black guillemots have been declining … Edith’s checkerspot butterflies moving north … Sachem skipper butterflies moving north … Intertidal organisms shifting northward … Mexican jays are breeding earlier … Mexican voles expanding their range … Hawks & other birds moving northward … Prairie grasses are on the decline … Fire ants are expanding their range … Palm trees are dying … Polar bears losing weight & bearing fewer cubs … Caribou populations are declining … Mosquitoes & dengue fever are moving … Coral reefs are bleaching and declining … Subalpine forests moving to higher elevations …

+ and – Feedbacks : 

+ and – Feedbacks As artic ice melts, land becomes darker, earth absorbs more energy Colder seas absorb more CO2 than warmer seas. Warmer seas will leave more CO2 in atmosphere, leading to more warming Soil respiration releases CO2. Microbes respire more at higher temperatures. Clouds will reflect light and lower temperatures Clouds will trap in more heat?

Kyoto Protocol : 

Kyoto Protocol Kyoto protocol came into to enforcement February 2005 when Russia signed up. 30 industrialized countries signed up Must reduce their emissions of 6 greenhouse gases to 95% of 1990 levels by 2012 Has the U.S. signed on?

EPA Must Regulate Carbon Pollution : 

EPA Must Regulate Carbon Pollution Supreme Court ruled April 2 (2007) that the EPA must consider putting controls on carbon dioxide and other gases in automobile exhaust. Previously, under White House orders, EPA claimed it didn’t have this authority and that carbon dioxide is not an air pollutant.

What is your C footprint? : 

What is your C footprint? www.safeclimate.net/calculator/index.php