Global Warming

An iceberg melts in Kulusuk, Greenland, near the Arctic Circle.

•Global warming is a rise in global temperatures that could result from the increased absorption of radiation due to higher levels of greenhouse gases.

•50% of all radiation that reaches the Earth is absorbed. The remaining 50% is reflected back out to space.

•The greenhouse effect is the natural heating of Earth’s surface caused by the retention of heat by certain atmospheric gases called greenhouse gases.

•Scientists theorize that any increase in the amount of greenhouse gases, particular carbon dioxide (CO2), would result in the increased absorption of radiation.

1. Greenhouse Effect is responsible for the Earth’s warm and livable climate.

2. Greenhouse gases include:a.Water vaporb.Methanec.Carbon dioxided.Ozonee.Nitrous oxide

3. The sun sends radiation.

4. Atmosphere:

The Atmosphere reflects the sun’s energy.

4. Some of the heat is reflected by the atmosphere.

5) On Earth: Energy that passes through, are absorbed by the ground, water, gases, and plants.•A portion of the solar radiation that reaches the Earth’s surface such as ice, snow, and ocean are reflected.

Radiation trigger the greenhouse gases to move. As a result, the atmosphere is heated.

6. Radiation trigger the greenhouse gases to move. As a result, the atmosphere is heated.

Consequences of Global Warming:

• Unless we act now, your children will inherit a hotter world, dirtier air and water, more severe floods and droughts, and more wildfires.

ecosystem shifts and species die-off

I. CLIMATE PATTERN CHANGES

a. warmer temperatures

b. drought and wildfire

c. more intense rainstorms

Greater evaporation as a result of global warmingcould increase the risk of wildfires.

II. HEALTH EFFECTS

a. deadly heat waves and the spread of disease

Greater evaporation as a result of global warmingcould increase the risk of wildfires.

More frequent and more intensive heat waves could result in more heat-related deaths. Photo: Gary Braasch, Chicago, July 1995. See the World View of Global Warming website for more Gary Braasch photos illustrating the consequences of the changing climate.

III. WARMING WATER

a. more powerful hurricanesb. melting glaciersc. sea-level rise

The satellite photo at far left shows the Larson B ice shelf on Jan. 31, 2002. Ice appears as solid white. Moving to the right, in photos taken Feb. 17 and Feb. 23, the ice begins to disintegrate. In the photos at far right, taken Mar. 5 and Mar 7, note water (blue) where solid ice had been, and that a portion of the shelf is drifting away. Photos: National Aeronautics and Space Administration

Ancient ice shelf breaks free

A giant ice shelf the size of 11,000 football fields has snapped free from Canada's Arctic, scientists said. The mass of ice broke clear 16 months ago from the coast of Ellesmere Island.

•Credit

•Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC

The Arctic’s largest ice shelf is breaking up. The Ward Hunt Ice Shelf is a remnant of the compacted snow and ancient sea ice that extended along the northern shores of Ellesmere Island in Northern Canada until the early twentieth century.

IV. ECOSYSTEM DISRUPTION

a. ecosystem shifts and species die-off.

Warmer temperatures may cause some ecosystems, including alpine meadows in the Rocky Mountains, to disappear.

For more Environmental Facts:

Natural Resources Defense Council

This file photo provided by Mary Sage shows a polar bear watching a whaling crew off shore near Barrow, Alaska, Monday, May 22, 2006. Polar bears are in deep trouble because of global warming and other factors and deserve federal protection under the Endangered Species Act, the Bush administration is proposing Wednesday, Dec. 27, 2006. (AP Photo/Courtesy of Mary Sage, Joseph Napaaqtuq Sage)

Polar Bears are dying at alarming rates due to Global Warming.

Blue Man Group – Earth to America (Global Warming) 1:49 min

How Do Ice Cores of Glaciers Tell Us about Past Climates?

•Research scientists collect and study glacial ice cores.

•Data from these ice cores provide one of the most complete records of past climate conditions. Of greatest interest are the deep cores obtained by drilling programs in Summit, Greenland and Vostok, Antarctica.

•The Vostok ice core provides the longest continuous record of Antarctic climatic history.

•Analysis of the core has been completed to a depth of 3350 meters, representing approximately 440,000 years of climate history.

                       

                             

Vostok ice core drilling site, Antarctica

Ice cores reveal the story of Earth's climate in reverse order.

The uppermost layers of the core tell the most recent history, with increasingly deeper layers providing a record of progressively older periods (Law of Superposition).

Scientists can determine the amount of carbon dioxide that was in the air during different time periods by analyzing gas bubbles trapped in ice cores. Carbon dioxide is a greenhouse gas that plays a major role in the atmosphere’s energy balance.

Scientists can reconstruct a record of temperatures that occurred in the past by analyzing the ratio of oxygen isotopes trapped within air bubbles in the ice (O16 & O18).

The graph below shows how the temperature has changed over the past 165,000 years. The graph shows temperature anomalies—variations in the temperature above or below Vostok’s present day average temperature of -56ºC.

LOW

High

Temperature and carbon dioxide data are plotted together on this graph. This makes it easier to compare the two variables and how they may be related.

Recent Changes in Atmospheric Carbon Dioxide

Scientists have been precisely measuring the amount of carbon dioxide in the atmosphere since 1958. The results of these studies are plotted on the graph below. The yearly average CO2 level is represented by the smooth black line, and seasonal changes appear as small peaks and dips.

Ice core research projects are working to extend the record of global climate further back in time and over more of Earth’s surface.

To learn about their most recent discoveries, visit the links provided:

Explore these links for more information about ice core projects and climate research:

Graph of Vostok ice core data extending back for 400,000 years Greenland Ice Sheet Project 2 North Greenland Ice Core Project Taylor Dome Ice Core Project European Project for Ice Coring in Antarctica (EPICA) World Data Center for Paleoclimatology Collection of photographs about polar ice core research National Ice Core Laboratory