What is climate change?
Throughout the history of the Earth, the climate has changed many times, ranging from ice ages to periods of warmth. "Climate change" is any significant change in the temperature, precipitation, wind, or other factors that lasts for long periods of time. For millions of years, the climate has been influenced by natural events, such as volcanic eruptions, changes in the Earth's orbit, and changes in the amount of the Sun's energy reaching the Earth.
Earth materials, such as land and water, absorb energy from the Sun. These Earth materials then give off some of this energy as heat. Anyone who has walked barefoot on a hot beach knows that! Heat-trapping gases in the atmosphere, often called "greenhouse gases," act as a blanket, trapping heat within the Earth system. The more greenhouse gases in the atmosphere, the more heat is trapped.
What are the causes of global climate change?
Recent changes in climate do not appear to be entirely natural. Scientific data shows that since the Industrial Revolution, the rate at which humans burn fossil fuels, like oil, gas, and coal for energy, has increased. Burning fossil fuels releases huge amounts of heat-trapping gases into the atmosphere. An example of a heat trapping gas is carbon dioxide.
In the past 100 years, the Earth's average temperature increased by 0.6°C. The decade of 1990- 1999 was the warmest decade in 150 years. Sea levels have risen .1 to .2 meters. Ice caps and mountain glaciers are melting. Habitats for marine organisms are changing.
Climate change is a very important topic for policy makers and government officials around the world. A changing marine food web affects fishing, biodiversity, and water-related tourism. Coastal areas face the threat of rising sea levels. Agriculture and economics may also be widely affected. All these aspects of life are touched by climate change.
How does climate change affect biodiversity and marine organisms?
Climate change affects all living organisms in an ecosystem. Changes in temperature, precipitation, ice cover, etc. impact the breeding, migration, and feeding behaviors, as well as other life activities of many species. As the climate changes, species will have to adapt or migrate to other region. If they cannot, they may become extinct.
Scientists are already observing changes that affect marine organisms. Climate change causes sea ice to form later in the fall and melt earlier in the spring. As a result, polar bears have less time to hunt and store energy for the summer and fall when food is scarce. Some species of seal, such as the harp seal, are also affected by changing ice conditions. Studies show that the survival rate of sea pups is not as high as in years when sea ice is in short supply. Penguins, albatross, and whales also rely on sea ice as part of the ecosystem which supports their food web. As the climate warms, and ice changes, these food webs are shifted out of balance, affecting many species.
As sea levels rise, sea turtles and seabirds may have less beach space to build their nests. Increasing storms and storm surge may wash away nests already built. Of course, their food chains may be affected in ways we cannot predict.
What are we doing about climate change?
Globally, governments are writing laws and developing treaties to lessen their contribution to greenhouse gas emissions. The Kyoto Protocol, for example, is an agreement between some countries to take specific steps towards lowering emissions. Efforts such as increasing renewable energy use, taxing carbon dioxide emissions, and emission allowance trading programs have led to success in recent years. Unfortunately, certain countries, including the United States, do not take part in the Kyoto Protocol.
Scientific research is continuing in order to determine the possible outcomes of continued warming for life on the planet. The more information scientists and policy makers have about climate change, the more hopeful it is that governments will take the data seriously and institute change.
What can students do about climate change?
- Reduce electricity use: Chances are that the electricity in your home and school is produced from fossil fuels, such as coal or natural gas. By cutting down on the amount of electricity you use, you can reduce the amount of greenhouse gases entering the atmosphere and save money.
- Find out where your energy comes from: Call your local power company and find out the source of your electricity. If possible, ask your family or school district to switch to renewable energy sources, such as solar or wind power, which do not release greenhouse gases into the atmosphere.
- Reuse and recycle: Reuse food containers and plastic bags. Recycle cans, bottles, and newspaper. It takes much more energy to produce brand new items than to recycle them. If your school does not have a recycling program, start one!
- Walk or bike when possible: Both of these activities are fossil-fuel free, unlike getting a ride in a car.
- Choose products with less packaging: Plastics are produced from petroleum, a type of fossil fuel. Pick packages of food, toys, and other items in less packaging.
- Choose local foods: Help your family choose foods grown in local areas. The best places to go are farmer's markets and farm stands. Food flown or trucked in from far away requires a lot of extra energy and fossil fuels.
- Share what you have learned with others!!
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