The following activities contribute to the Greenhouse Effect.

• Burning natural gas, coal and oil. Driving cars and burning fossil fuels contribute to the warming of the Earth.
• Some farming practices and land-use changes. One of the primary meat sources in the US, the beef industry is one of the largest methane-producers.
• Many factories produce long-lasting industrial gases. Some gases will still be in the atmosphere long after we’re dead.
• Deforestation. “Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.”
• Population growth. The more people there are. the more cars we need, the more food we must produce, the more industries we must have.

In conclusion, West says, “Ultimately, more greenhouse gases means more infrared radiation trapped and held, which gradually increases the temperature of the Earth’s surface and the air in the lower atmosphere.”

The Sierra Club offers an 0nline form that you fill out so you can help save the polar bears.

Here is the text of the letter:

Help Save the Polar Bear

Dear [Decision Maker],

The polar bear is one of nature’s most beautiful creations. But now global warming poses a serious threat to these and other arctic animals.

The alarming loss of ice due to global warming in the Arctic Ocean harms bears by forcing them to swim long distances to hunt. Increasingly polar bears are found drowned, starving, or underweight. Scientists make the dire prediction that we could lose this stately and unique animal as soon as the end of this century unless we put the brakes on global warming pollution and stabilize sea ice decline.

We support all efforts to protect the polar bear. While listing the polar bear as a threatened species acknowledges for the first time that global warming poses a threat to its survival, unfortunately the Endangered Species Act simply can’t do enough to save it.

As a nation, we must decrease our reliance on the dirty energy sources that cause global warming. Otherwise, the polar ice caps will continue to melt away. Some analysts believe the arctic icecap could totally disappear by the year 2050, which will be a catastrophe for polar bears and many other animals, including humans.

We urge you to act immediately to save the polar bear by designating it as a threatened species, putting in place real measures to protect the bear and aid its recovery, and by using smart energy solutions to stop global warming.