Atmospheric Processes Involved in Global Warming

Top issues in science Alternative energy Stem cells & cloning Global warming

Top issues in science Nanoscience and nanotechnology Genetically modified plants Using animals in research

The public ignores many science issues Pluto is NOT a planet First face transplant Element 118 discovered

But not global warming...

A balanced presentation?

The “truth” in An Inconvenient Truth

Temperature trends

Global Cooling fears “There are ominous signs that the earth’s weather patterns have begun to change dramatically and that these changes may portend a drastic decline in food production...” Newsweek, April 28, 1975

Ten hottest years

Deadly heat waves

Extreme high temperatures Not one of the world’s highest temperatures has occurred in the past 30 years! U.S. National Oceanic and Atmospheric Administration

Hurricane warnings

The Deadliest Hurricanes Rosenberg Library, Galveston Galveston hurricane, 1900: 8,000 killed Bangladesh cyclone, 1970: 300,000 killed

Deadly weather disasters

Yangtze River flood, 1931: 3.7 million killedYangtze River flood, 1931: 3.7 million killed Vietnam flood, 1971:100,000 killedVietnam flood, 1971:100,000 killed Great Iran Flood, 1954: 10,000 casualtiesGreat Iran Flood, 1954: 10,000 casualties China typhoon 1912: 50,000 killedChina typhoon 1912: 50,000 killed China typhoon 1922: 60,000 killedChina typhoon 1922: 60,000 killed India drought 1914: 250,000 diedIndia drought 1914: 250,000 died Chinese famine 1907: 24 million diedChinese famine 1907: 24 million died Soviet Union drought : 3 million diedSoviet Union drought : 3 million died Great Drought in western Sahara Desert : 100,000 died from starvation and diseaseGreat Drought in western Sahara Desert : 100,000 died from starvation and disease Source: World Meteorological Organization Deadly weather disasters

Big Questions Why do scientists disagree about the causes and effects of global warming? Why is the issue so complicated? Kerry Emanuel: Phaeton’s Reins: The human hand in climate change Boston Review,

Climate Change The earth is 4.5 billion years old. During the past 3,000,000 years, the earth has had both mild climates and ice ages.

Ice ages Eccentricity (shape) of the earth’s orbit: 100,000 year cycle Precession (wobbling) of the earth’s axis: 23,000 year cycle Obliquity (tilt angle) of the earth’s axis: 100,000 year cycle

The Greenhouse Effect ~ 0.55  m ~ 10.0  m Earth with no atmosphere Earth and atmosphere together

Greenhouse gases H 2 O: The most important greenhouse substances (liquid and vapor). H 2 O vapor absorbs infrared radiation warming H 2 O liquid reflects sunlight into space cooling H 2 O is constantly recycled between the atmosphere and the oceans The concentration of water vapor is limited by temperature CO 2 : 2nd-most important greenhouse gas absorbs infrared radiation warming lifetime up to 200 years

Do clouds cool or warm the atmosphere?

Feedback processes Positive feedback: an amplifying process Negative feedback: a process that reduces itself body heat evaporation, cooling REDUCED Negative feedback: a reducing process

Ice-Albedo Feedback Albedo: % of sunlight reflected. White surfaces: large albedo. Dark surfaces: small albedo.

Ice-Albedo Feedback Lots of ice in the Arctic

Ice-Albedo Feedback Atmospheric temperatures increase Sea ice melts Albedo decreases Earth absorbs more energy

Cloud feedbacks Clouds reflect sunlight cooling Clouds absorb IR radiation warming Polluted clouds reflect more sunlight cooling

Sulfate (SO 4 ) aerosols sulfate aerosols reflect sunlight cooling sulfate aerosols cause more clouds to form cooling sulfate aerosols reduce the size of cloud droplets cooling

Chaotic system: limited predictability small differences increase quickly

Parameterization

Current status

So what should we do? Elect politicians who understand science Conserve the earth’s resources as much as you can Pollute as little as you can Remember that popular movies and books like The Day After Tomorrow and State of Fear are entertainment, not science.

What else? Read what the scientists write (like the IPCC report: Be skeptical Trust your own opinion more than Hollywood’s, Michael Crichton’s, or even Al Gore’s Enjoy all the beautiful things in life Have a nice day!