Crib Sheet: Global Warming

It’s gettin’ hot in herre! Get the facts.

By Ana Unruh Cohen, Director for Environmental Policy, Center for American Progress

What is climate change?

Most people use “climate change” or “global warming” as a short hand for the impacts caused by the release of greenhouse gases from human activities, like burning fossil fuels. Though climate change is speeding up now at a dangerous pace, the climate of the Earth has changed throughout its history. For example, twenty thousand years ago, at the height of the last ice age, glaciers covered much of Canada and the northern United States.

What are greenhouse gases?

There are a number of greenhouse gases that occur naturally and are the major contributors to the greenhouse effect – water vapor, carbon dioxide (CO 2), and ozone (at high altitudes, not smog at ground level). Methane and nitrous oxide play a minor role and are mostly produced in the agricultural sector. Some man-made industrial gases, like chlorofluorocarbons (more famous for their creation of the ozone hole), also contribute to the greenhouse effect. Most efforts to control greenhouse gases have focused on the CO 2 emissions from human activities because they have the most affect and we have the greatest control over them.

Are we humans really responsible for the recent warming?

Yes. Since the Industrial Revolution, combustion of fossil fuels, burning of forests and land use changes, like the growth of cities, has increased the concentration of greenhouse gases at an unprecedented rate and to levels that the Earth hasn’t seen for 650 thousand years. As a result, the top ten hottest years in in the past two hundred have all occurred since 1990.

But is climate change really a pressing issue right now?

Some industry groups, conservative think tanks and politicians continue to raise doubts about the state of the climate change science, and the Bush administration has actively denied the problem, even resorting to censoring portions of a critical EPA report on the subject. However, the United States ’ most distinguished scientific bodies and professional organizations, including the National Academies of Science, the American Association for the Advancement of Science, the American Geophysical Union and the American Meteorological Society, have all issued statements acknowledging the compelling scientific evidence of human modification of climate. Visit Exxon Secrets for an interactive flash presentation tracing the connections between corporations and corporate funded climate change skeptics. Read real scientists debunking the latest climate change science outrages in real time at Real Climate.

How do greenhouse gases raise the Earth’s temperature?

Greenhouse gases absorb heat and prevent it from escaping into space. They act like a blanket – too thick a blanket and you get the scorching temperatures of Venus, too thin a blanket and you get the freezing temperatures of Mars. As we pump more greenhouse gases into the atmosphere, we increase the thickness of Earth’s “blanket”.

How much have we already warmed the Earth?

Scientists estimate that we have already warmed the Earth nearly 1.5°F (0.8°C) over the last 150 years. In that time, we have seen sea level rise, snow cover decrease, mountain glaciers and sea ice retreat, and droughts increase.

How hot could it get?

By the end of the century when CO 2 concentrations in the atmosphere could be double what they were before the Industrial Revolution, temperatures could rise 2.5 to 10.4°F (1.4 to 5.8°C). If that happens, LA will look more like Death Valley. London might grow palm trees, and crocodiles could start hanging out in swamps in the Canadian Arctic, just like they did 25 million years ago when the world last saw CO 2 levels that high.

What impacts will the rising heat have?

Last year, climate scientists outlined the following impacts from global warming: with only a 1.8°F rise, which could occur within 25 years, could lead to food production declines, water shortages, and loss of GDP in developing countries. With a 3.6°F rise, which could occur before 2050, we could see substantial losses of Arctic sea ice, widespread bleaching of coral reefs, more frequent forest fires, and rivers that may become too warm to support trout and salmon. In the developing world, another 1.5 billion people could face water shortages and profound GDP losses. 5.4° rise, which could occur before 2070, could lead to irreversible damage to the Amazon rainforest, total destruction of many of the world’s coral reefs, hunger, 5.5 billion people living in regions with crop losses and another 3 billion at risk of water shortages.

Will the Kyoto Protocol prevent this?

No. Kyoto was designed as a first step in lowering greenhouse gas emissions from developed countries, which have historically produced the most greenhouse gases and have the greatest capacity to invest in limiting emissions. It is still important though because, for the first time, over 30 countries, but not the United States, will have legally binding commitments to reduce their greenhouse gas emissions. It will also start a world-wide market for trading greenhouse gas emission credits and set up a mechanism for developed countries to help developing countries enhance their energy with clean sources, which could lead to real breakthroughs in emission reductions.

What more do we need to do?

To really stabilize greenhouse gas concentrations at a level that the world can cope with, all countries must commit to taking action on their emissions. The United States, the largest emitter in the world with 25% of world emission and only 5% of the world’s population, has to get serious about decreasing emissions. The smart way to achieve reductions in a quick and economically feasible way is to institute a national cap and trade system. A national renewable energy portfolio standard would help deploy the renewable energy technology we already have, as well as providing incentives to develop the next generation of clean energy technology. At the same time rapidly growing countries like China, India and Brazil need to accept their increasing responsibility for emissions and commit to growing their economies as cleanly as possible. Developed countries need to help them do this, as well as, help developing countries adapt to the impact of climate changes in the future. For more ideas, check out the International Climate Change Taskforce’s report, Meeting the Climate Challenge, at www.americanprogress.org/climate.

Is anything happening in the United States to reduce emissions?

Yes! Governors are taking matters into their own hands. A bipartisan coalition of 8 northeastern states—four with Republican governors and four with Democratic ones—is taking matters into their own hands to control global warming. The consortium, called the Regional Greenhouse Gas Initiative, will implement a regional cap-and-trade system to control greenhouse gas emissions. The states involved see "environment, health and economic"benefits in taking action. And 22 states have Renewable Portfolio Standards (RPS) which mandate that a certain percentage of electricity be produced from renewable sources. By 2017, these standards alone will lead to reductions of 75 million metric tons (MMT)—the equivalent of taking 11.1 million cars off the road or planting trees over an area a little larger than West Virginia.

Is anything happening globally to address climate change?

Yes! The United Nations Climate Change Conference hosted a two-week conference at the end of 2005 in Montreal. Despite the Bush Administration’s attempts to undermine the proceedings,, the Conference adopted more than 40 decisions at what the acting head of the UN Climate Change Secretariat described as “one of the most productive UN Climate Change Conferences ever”. Among other decisions was the adoption of the Marrakech Accords which allow for the formal implementation of the Kyoto Protocol to proceed. Moreover, all countries, including the United States and developing countries, agreed to open dialogue on long-term and cooperative action to address climate change. Countries participating in the Kyoto Protocol also started their consideration of future commitments beyond the first period which ends in 2012.

What about business? Isn’t it too expensive to reduce CO 2 emissions?

Much of the business community wants to address global warming. Some industry and conservative think tanks have repeatedly claimed that a mandatory reduction in greenhouse gases would have a negative economic impact. But the international business community understands that the consequences of inaction would be far worse. Experts at a major insurance industry conference agreed that extreme weather patterns could cost the insurance industry an additional $25 billion annually if global warming is unchecked. Some companies aren’t waiting for government action but are reducing greenhouse gas emissions on their own for the betterment of the world and their bottom lines. By 2003, DuPont had reduced its emissions by 72% from 1990 levels, and energy giant BP reached its emission reduction goal, 10% below 1990 levels, by 1998.

What can I do?

Personal choices do make a difference. Walk, bike or carpool whenever possible. Switch off unnecessary lights. You might even consider unplugging your electronics when they are not in use. Most use energy when they are plugged in even if you aren’t using them. On campus, encourage the administration to make the campus as energy efficient as possible, even with small changes like installing compact fluorescent, instead of traditional light bulbs. Try to get your school to buy renewable energy from their utility company wherever possible. New buildings and major renovations should be as close to zero-energy as possible. Green design increases upfront construction costs by only 2% but saves a lot more in the long run. Finally, agitate at all levels of government for your representatives to take the dangers of climate change seriously and take action now to decrease greenhouse gas emissions.

To find groups that can help you start organizing on your campus, read our article "Student Energy". To take action on climate change, check out the Campus Climate Challenge, a Campus Progress-supported campaign.

Illustration by Scott Thigpen

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