Understanding Global Warming A Live Green, Live Smart Presentation
The Greenhouse Effect • To understand global warming, we must first understand the Greenhouse Effect. • The Earth’s naturally mild temperature and climate is a result of the Greenhouse Effect. • Gases in the atmosphere, like carbon dioxide (CO2), methane (CH4), and ozone (O3), cover the Earth like the glass walls of a greenhouse. • These gases serve two purposes: they protect the planet from receiving too much sunlight (and heat), and they trap sunlight to prevent it from escaping into space. • Normally these two actions are balanced perfectly so the Earth’s climate is warm and livable.
The Greenhouse Effect • A rapid change in greenhouse gas concentration causes the system to become unbalanced. • If the amount of greenhouse gas decreases, the Earth cools down, and can enter an Ice Age. • If the amount increases, the Earth warms up - this is called Global Warming. • If the Greenhouse Effect becomes too unbalanced in either direction, the Earth may become uninhabitable for humans.
Humans and Global Warming • Most scientists now believe the Earth is entering a period of global warming. • Many also believe that human activities are causing the Earth to warm at an unnaturally rapid pace.
How Are Humans Contributing to Global Warming? • The primary human-related cause of global warming is the burning of fossil fuels like oil, coal, and natural gas. • When fossil fuels are burned, they release carbon dioxide into the air, which collects in the atmosphere as a greenhouse gas. • We use fossil fuels every day to power our cars, to light and heat (or cool) our homes, to manufacture goods, and to grow food. • We have also put more methane, ozone, and other greenhouse gases into the atmosphere through industrial and agricultural production.
How Are Humans Contributing to Global Warming? • Carbon dioxide levels in the atmosphere have increased 30% since the start of the Industrial Revolution. • Methane levels have increased 150%. • The result of this increase in greenhouse gas is that less of the sun's heat is able to escape through the atmosphere into space. • This heat stays trapped in the Earth’s climate. • As more greenhouse gases enter into the atmosphere, more of the sun’s heat is trapped – and the Earth gets warmer and warmer. • In the last century the planet’s average temperature rose 1.3F. • This may not seem like much, but we are already experiencing the effects of this increase. • The difference in temperature between the last Ice Age and today’s climate is only 5F.
When the Greenhouse Effect is altered so drastically and so suddenly, the entire planet is put in danger.
Dangers of Global Warming • Among the dangers posed to the climate by increasing temperatures are: • Disruption of the Carbon Cycle • Changes in weather patterns, including more frequent severe storms, such as hurricanes • Droughts and water shortages in some places • Increased rainfall in others • Rising ocean levels • Vast, complex and often subtle changes are difficult to comprehend. • If we look at these changes in more specific terms, the degree of devastation becomes plainer. • The following slides are but a few examples of the effects of global warming on the climate.
The Carbon Cycle • Normally the planet has ways to deal with excess carbon in the atmosphere. • Plants “eat” carbon dioxide and produce oxygen, which animals “eat,” producing carbon dioxide. • This is called the Carbon Cycle. • Trees and ocean algae do most of this eating. • The amount of carbon dioxide in the atmosphere today has overloaded the Carbon Cycle – it cannot keep up. • Deforestation and pollution in the oceans have also helped to reduce the effectiveness of the Carbon Cycle.
Changes in Weather • Since 1980 we’ve had 22 of the warmest years on record. • Six of the warmest have been within the last eight years. • Storms and hurricanes in North America and the Atlantic Ocean have become more frequent and more violent. • Fatal consecutive summer heat waves have beset Europe. • Snow cover in the Northern Hemisphere has decreased 10% since 1966. • The Arctic Summer melting season increased between 1979 and 1998: the shortest was 57 days in 1979; the longest, 81 days in 1998.
Droughts • According to the National Center for Atmospheric Research, Earth's dry, arid lands expanded from less than 15% of the total in the 1970s, to 30% in 2002. • In 2002, record temperatures brought about severe droughts, causing a worldwide harvest loss of 90 million tons. In 2004 there was a loss of 34 million tons due to drought caused by increased temperatures. • A study from corn- and rice-producing countries noted a 17% drop in crop yields with just a 1.8F temperature rise.
Water shortages • A study done by the United States Geological Survey showed that the number of glaciers in Glacier National Park decreased from 150 in 1850, to less than 50 today; they predict that there will be none in 30 years. • As the glaciers melt, less clean water is available for human use, and sources for crop irrigation are lost. • Worldwide, more than 1.5 billion people currently depend upon glacial sources for water. • Much of the American West is habitable only through water from glacial sources. • 70% of the snow packs of the Western United States will be gone by the middle of the century.
Rising Ocean Levels • The ocean could rise as much as one meter in this century, due to melting in the polar ice caps. • This may not sound like much, but the repercussions are huge. • Millions of people in crowded costal areas like Bangladesh, Shanghai, even Florida and Manhattan will be forced to relocate as these areas become uninhabitable. • 40-50% of costal wetlands could be wiped out, killing off plant and animal species and leaving inland areas more susceptible to storms like hurricanes and tsunamis.
Life on a Warm Planet • Global warming will have a serious effect on the world’s plant and animal life. • Species biodiversity will suffer as hundreds of thousands, if not millions, of species become endangered or go extinct. • Humans will be especially affected by global warming.
Biodiversity • Because global warming is altering the climate so rapidly, many species of plants and animals will have no time to adapt. • These species risk endangerment and extinction. • Many of these species already face hardship thanks to deforestation and other human activities. • The first extinction attributed entirely to global warming was the golden toad of Costa Rica. • Polar habitat animals, such as Arctic foxes, penguins, and polar bears, are literally seeing their homes melt away. • Rising temperatures in the ocean are killing off essential organisms like algae, plankton, and coral. • Animals higher up in the food chain will see a loss of food supply and soon face the extinction risk as well. • Meanwhile, other species will thrive in the new climate and migrate around the world, throwing the planet’s biodiversity off balance.
The Human Toll • The species accelerating global warming stands to lose much due to climate change. • Entire regions could become completely uninhabitable to us for reasons including: Rising sea levels Desertification Intense heat Loss of usable water Loss of usable soil
The Human Toll • Clean freshwater will become a precious and increasingly rare commodity as our glaciers, lakes, rivers, and groundwater sources dry up. • Crop and livestock species will become less diverse and more susceptible to disease and climate change. • Diseases like malaria, already one of the world’s worst killers, will multiply around the world as temperate regions get warmer.
Solutions • Most experts believe there is still time to avoid drastic climate change. • However, there is no “magic bullet” to solve the coming crisis and reverse the damage we have done to the environment. • Instead, a series of changes must be implemented now. These necessary changes range from large-scale to small-scale. • The focus of these changes is to dramatically reduce our greenhouse gas emissions.
Solutions • To stabilize the climate at at its present level, we must cut greenhouse gas emissions by 70%. • To actually reduce atmospheric greenhouse gases, we must cut emissions still further. • Solutions fall into two general categories: • Reducing energy use • Investing in alternative energy
Large-Scale Solutions • The Kyoto Protocol is the first international agreement to cut emissions of carbon dioxide and five other greenhouse gases. • The signatories agree to cut their emissions to 1990 levels. • The United States and Australia are the only countries yet to sign Kyoto. • The European Union plans to reduce emissions 20% by 2020. They hope to do this through a number of initiatives: • Add 15,000 megawatts of wind power (enough to supply half the population of Europe) • Increase ethanol production five-fold • Increase biodiesel production three-fold • Germany plans to cut its emissions 67% by 2050 by cutting energy use and using renewable energy. • Iceland already heats 93% of its homes with renewable geothermal energy. • Many nations are investigating “cap and trade” programs that limit greenhouse gas emissions.
Small-Scale Solutions • Fixing the climate is not just an international matter. Is is within reach of the average person. • There are many things you can do to reduce your greenhouse gas emissions: • Drive less or get a fuel-efficient car • Eat local foods as much as possible • Use an efficient heating and cooling system in your home • Use fluorescent light bulbs • Buy renewable power from your electric utility or install renewable energy sources in your house • This is far from a complete list of options. Learn more ways to reduce your greenhouse gas emissions at www.livegreenlivesmart.org
America ranksnumber one as a producer of greenhouse gases. • Americans must participate in efforts to halt and reverse global warming. • If a basic understanding of the causes and dangers of rapid climate change is paired with the knowledge of better choices, we can immediately begin the work of saving the planet for future generations.
Thank you for your time and attention. This has been a Live Green, Live Smart presentation. www.livegreenlivesmart.org