This book should really be called Climate Change for Dummies. Although global warming is the common term for the climate changes that the planet's experiencing (and scientists agree that average global temperature will increase with the build-up of greenhouse gases), the term doesn't tell the whole story. The Earth's average surface temperature is going up, but some areas of the planet may actually get colder or experience more extreme bouts of rain, snow, or ice build-up. Consequently, most scientists prefer the term climate change. In the following sections, we look at how different places around the world will experience climate change.
^CRIJ"/^ We want to warn you, much of this section is pretty depressing. But nothing is exaggerated — the information here is all based on peer-reviewed scientific reports. Just how serious could the global impact of climate change be? The first global comprehensive scientific conference, which was held in Toronto, Canada, in 1988, described the climate change issue in this way: "Humanity is conducting an unintended, uncontrolled, globally pervasive experiment whose ultimate consequences could be second only to a global nuclear war."
In the U.S. and Canada, average temperatures have been rising because of climate change. As a result, the growing season has lengthened; trees have been sucking in more carbon, and farms have been more productive. The warmer weather hasn't been all good news, however. Many plants and animals are spreading farther north to adapt to climate changes, affecting the existing species in the areas to which they're moving. And increased temperatures have already been a factor in more forest fires and damage by forest insects, such as the recent pine beetle epidemic in the interior of British Columbia, Canada. (See Chapter 8 for more information about how global warming will affect animals and forests.)
Scientists project that the U.S. and Canada will feel the effects of climate change more adversely in the coming years. Here are some of the problems, anticipated to only get worse if civilization doesn't dramatically reduce greenhouse gas emissions:
I Droughts: Rising temperatures are increasing droughts in areas that are already arid, putting even larger pressure on scarce water sources in areas such as the U.S. Southwest.
I Evaporating lakes: The cities in the great heartland of the Great Lakes Basin will face retreating shorelines when the water levels of the Great Lakes drop because of increased evaporation. Lower water levels will also affect ship and barge traffic along the Mississippi, St. Lawrence, and other major rivers.
I Floods: Warmer air contains more moisture, and North Americans are already experiencing more sudden deluge events, causing washed out roads and bridges, and flooded basements.
I Major storms: Warming oceans increase the risk of extreme weather that will plague coastal cities. Think of Hurricane Katrina, arguably the most devastating weather event ever to hit a North American city. In a possible sign of what's to come, the super-heated waters of the Gulf of Mexico whipped Katrina into a hurricane with a massive punch while it crossed from Florida and made landfall in Louisiana, ultimately doing more than $200 billion worth of damage.
Not all extreme weather events are hurricanes. Global warming is expected to increase ice storms in some areas and thunderstorms in others.
I Melting glaciers: Glaciers in the Rockies and in the far North, in both Canada and the U.S., are in retreat. Glacier National Park could some day be a park where the only glacier is in the name. When glaciers go, so does the spring recharge that flows down into the valleys, increasing the pressure on the remaining water supplies. People who depend on drinking water from rivers or lakes that are fed by mountain glaciers will also be vulnerable.
I Rising sea levels: Water expands when it gets warmer, so while global average temperatures rise, warmer air warms the ocean. Oceans are expanding, and sea levels are rising around the world, threatening coastal cities — many of which are in the U.S. and Canada. This sea level rise could become far more devastating should ice sheets in Greenland and Antarctica collapse.
Changes across northern Canada and Alaska are more profound than in the south. We discuss these impacts in the section "Polar regions," later in this chapter.
On average, North Americans have many resources, in comparison to developing regions of the world, to help them adapt to climate change. The Intergovernmental Panel on Climate Change (IPCC) says Canada and the United States can take steps to avoid many of the costs of climate change, to better absorb the effects and avoid the loss of human lives. For example, North America could establish better storm warning systems and community support to make sure that poor people in inner cities have some hope of relief during more frequent killer heat waves. (See Chapter 10 for more information about what governments can do to help their countries adapt to the effects of climate change.)
South America has seen some strange weather in the past few years. Drought hit the Amazon in 2005, Bolivia had hail storms in 2002, and the torrential rainfalls lashed Venezuela in 1999 and 2005. In 2003, for the first time ever, a hurricane hit Brazil. Were these strange weather events linked to global warming? Scientists can't say with certainty, but these events are the kind expected to occur because of climate change. Scientists do project that extreme weather caused by climate change will increase. Events such as these may be signs of what's to come for Latin America.
Other changes in Latin America may be attributable to global warming. Rain patterns have been changing significantly. More rain is falling in some places, such as Brazil, and less in others, such as southern Peru. Glaciers across the continent are melting. This glacier loss is a particular problem in Bolivia, Ecuador, and Peru, where many people depend on glacier-fed streams and rivers for drinking water and electricity from small-scale hydroelectric plants. (See Chapter 9 for more about how global warming will affect humans.)
Scientists project that the worst is yet to come. The IPCC models anticipate that about half of the farmland in South America could become more desertlike or suffer saltwater intrusions. If sea levels continue to rise at a rate of 0.08 to 0.12 inches (2 to 3 millimeters) per year, it could affect drinking water on the west coast of Costa Rica, shoreline tourism in Mexico, and mangrove swamps in Brazil.
The threat to the Amazon from logging and burning has attracted the concern of celebrities such as Sting and Leonardo DiCaprio. But human-caused global warming could potentially do more damage than loggers. By mid-century, the IPCC predicts that parts of the Amazon could change from wet forest to dry grassland. Such a radical alteration would have an enormous impact on the millions of species of plants and animals that make this rich ecosystem their home. (We cover how ecosystems will be affected by climate change in Chapter 8.)
Recent findings have shown that climate change is already well under way in Europe. Years ago, the IPCC projected the changes that the continent is experiencing today: rising temperatures, increased intensity and frequency of heat waves, and increased glacier melt.
As for what's in store for Europe, the IPCC reports a 99-percent chance that Europe will experience other unfavorable climate changes. These changes may include the following:
^ Increased occurrence of rock falls in some mountainous regions because of melting permafrost loosening mountain walls.
^ More flash floods in inland areas.
^ More heat waves and droughts in central, eastern, and southern Europe. This will have an impact on health and tourism in southern Europe in particular.
^ Rising sea levels, which will increase erosion. These rising sea levels, coupled with storm surges, will also cause coastal flooding. The Netherlands and Venice will have greater trouble than other areas in Europe dealing with the rising sea level.
^ The loss of up to 60-percent of Europe's native species of plants and animals. Fisheries will also be stressed.
Countries sitting on the North Atlantic are likely to see a growth in fisheries, according to the IPCC.
These possibilities are all serious, but none of them represents the worst-case scenario — the Gulf Stream stalling. The results of this (stopping of a major ocean current) would be disastrous for Europe. (We look at the Gulf Stream in Chapter 7.) Although the Gulf Stream stalling is possible, the IPCC doesn't consider this possibility likely.
On a per-person basis, Africans have contributed the very least to global warming because of overall low levels of industrial development. Just look at a composite photo of the planet at night: The U.S., southern Canada, and Europe are lit up like Christmas trees, burning energy that results in greenhouse gas emissions. Africa, on the other hand, shows very few lights: some offshore oil rigs twinkle, and a few cities shine, but the continent is mostly dark.
Despite contributing very little to the source of the problem, many countries in Africa are already experiencing effects of global warming. Long periods of drought followed by deluge rainfall have had devastating impacts in places such as Mozambique. Coastal areas in East Africa have suffered damage from storm surges and rising sea levels.
Unfortunately, because of pervasive poverty and the scourge of AIDS, many s-^sj&k areas of Africa lack the necessary resources to help people living there cope with climate change. And the effects of global warming may act as a barrier to development and aggravate existing problems. At present, 200 million people (or 25 percent of the continent's population) lack drinkable water. Climate change may boost this figure by another 75 to 200 million people over the next 12 years. The IPCC projects that some countries could see a 50-percent drop in crop yields over the same period and a 90-percent drop in revenue from farming by the year 2100. (We look at how developing nations are affected by and are addressing global warming in Chapter 12.)
More people call Asia home than any other continent — 4 billion in all. This high population, combined with the fact that most of Asia's countries are developing, means that a lot of people won't be able to sufficiently adapt to climate change impacts. As in Africa, climate change may bring pressures to the continent that will slow down development.
The first concern is the future availability of drinkable water, which is already under pressure from population growth, pollution, and low or no sanitation. The IPCC projects that anywhere from 120 million to 1.2 billion people may find themselves without enough drinkable water within the next 42 years, depending on the severity of climate change. Already, rising temperatures are causing glaciers in the Himalayas, which supply water to 2 billion people, to melt. These disappearing glaciers are aggravating water shortages and will increase avalanches and flooding.
Rising sea levels will be a concern for coastal Asia. The IPCC reports that mangroves, coral reefs, and wetlands will be harmed by higher sea levels and warming water temperatures. On a brighter note, with rising saltwater intruding into fresh water, both fish that thrive in slightly salty water and the industry that fishes them are expected to benefit. Unfortunately, this slightly salty water won't be good for freshwater organisms, as a whole. (See Chapter 8 for more about the impact global warming will have on the oceans.)
Illnesses in Asia are also expected to rise because of global warming. Warmer seawater temperatures could also mean more, and more intense, cases of cholera. Scientists project that people in South and Southeast Asia will experience more cases of diarrheal disease, which can be fatal. (Chapter 9 offers more information about how global warming might increase disease.)
Australia & New Zealand
If you ask an Australian about global warming, you probably won't get any argument about its negative effects. Australia has already experienced increased heat waves, less snow, changes in rainfall, and more than seven years of persistent drought in four of its states. This heat and lack of precipitation will likely worsen while global warming's effects intensify. According to the IPCC, by 2030, water will be even scarcer in southern and eastern Australia and northern New Zealand than it currently is.
Climate change has also strongly affected the ocean. Sea levels have already risen 2.8 inches (70 millimeters) in Australia since the 1950s, and increasing ocean temperatures threaten the Great Barrier Reef. The reef is at risk of bleaching, and the possibility that it may be lost altogether is becoming more real. (See Chapter 8 for details.)
As in the United States and Canada, however, Australia and New Zealand may see some benefits from climate change. The IPCC reports that the countries may experience longer growing seasons, fewer occurrences of frost, and increased rainfall in some regions, which would benefit farming and forestry.
You probably aren't surprised to hear that when it comes to climate change, rising sea levels and more extreme storms create an enormous risk for small islands everywhere, such as the South Pacific island of Tuvalu. Some may simply disappear due to rising sea levels. If sea level rise does not inundate the islands, the impacts could still be severe:
i Forests vulnerable to major storms: Storms can easily topple island forests because a forest's small area doesn't provide much of a buffer (although some forests will expand because of warmer temperatures).
I Limited resources: Some islands can't adapt physically and/or financially.
I Proximity of population to the ocean: At least 50 percent of island populations live within a mile (1.5 kilometers) of water, and these populations are threatened by rising sea levels.
I Risks to drinkable water: The intrusion of ocean saltwater because of rising sea levels could contaminate islands' drinkable water, which is already limited on most islands.
I Reliance on tourism: Beach erosion and coral reef damage, two possible effects of climate change, would undermine tourism, which many islands rely on for their source of income.
I Vulnerable agriculture: Island agriculture, often a key part of the local economy, is extremely susceptible to harmful saltwater intrusions, as well as floods and droughts.
The planet's polar regions are feeling climate change's effects more intensely than anywhere else in the world. Warming temperatures are melting the ice and the permafrost that used to be solid ground.
The Arctic is home to many changes brought on by global warming, including the following:
1 Lost traditions: Some indigenous people who make their homes in the Arctic are having to abandon their traditional ways of life. The Arctic ice and ecosystem are both core to many of these people's cultures and livelihoods. For more on this issue, flip ahead to Chapter 9.
1 Melting ice: The Greenland ice sheet is quickly melting, adding to sea level rise. Arctic ice is also steadily losing ice volume. All of this melting is diluting ocean waters, affecting ocean currents.
1 New plant life: Greenery and new plants have been appearing in the Arctic in recent years. The tree line, which used to end about % of the way up Canada and Russia, is shifting farther north, but the soil is not there to support a forest.
Some people look forward to the changes that the Arctic is experiencing. Now that so much sea ice has melted, ships can navigate the Arctic Ocean more efficiently, taking shorter routes. Industrialists keenly anticipate being able to reach more fossil fuels below what used to be unreachable riches because of ice cover. Communities in the Arctic may be able to harness river flows that have been boosted or created by ice melt to run hydroelectric power. These short-term economic developments cannot outweigh the negative planetary impacts.
In the Antarctic, some scientists project major change because of global warming, thinking there's a chance that the western Antarctic ice sheet might melt by the end of the 21st century. The western Antarctic ice sheet is simply enormous. It contains about 768,000 cubic miles (3.2 million cubic kilometers) of ice, about 10 percent of the world's total ice. It appears to be weakening because warmer water is eroding its base. Most scientists dispute the notion that the entire sheet will melt, and many scientists are still researching the situation. Nevertheless, parts of the western Antarctic ice sheet are definitely melting, even if the whole thing isn't yet. The Greenland ice sheet is also melting — quickly. Both the western Antarctic and Greenland ice sheets are adding to sea level rise.
The melting polar ice is also endangering many species, such as polar bears and penguins, which rely on the ice as a hunting ground. (Chapter 8 offers more information about the ways the polar animals are being affected by global warming.)
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