GLOBAL WARMING AND CLIMATE CHANGE

Global Warming and Climate Change

Global Warming and Climate Change

Global Warming and climate change

The phrase global warming refers to a phenomenon in which the Earth's surface temperature increases from its long-term averages generally because of an atmospheric blanket of greenhouse gases (GHGs; primarily carbon dioxide, methane, and chlorofluorocarbons) that serve to trap reradiated solar energy from escaping into space. This blanket of greenhouse gases is responsible for providing Earth a generally temperate, stable, and life-sustaining climate. In common parlance, global warming is often used interchangeably with climate change. In the present context, though, it is used in a more limited sense as a driver of global climate change.

Various components of the earth's atmosphere are responsible for this greenhouse warming, though carbon dioxide is the principal greenhouse gas. The claim about global warming is that humans are now enhancing this greenhouse effect. For many thousands of years carbon dioxide levels have been low and reasonably constant, but they are now increasing enormously due to industrialization and the burning of fossil fuels (Houghton, 2004, 66).

The likely social impacts of global warming are diverse. As the very name suggests, there is likely to be an average increase in global temperature. Given the complexity of the climate system, this need not mean hotter weather everywhere, but the general trend will be warming with southern Europe forecast to become more like present-day North Africa over the next half-century, and with northern Europe set to become like the current Mediterranean. Rising temperatures will cause glaciers to retreat, threatening landscapes and undermining tourist enterprises. Weather patterns will shift: many places will become drier though the rain may be heavier when it does fall; agriculture will be strongly affected. The rise in global temperature will cause the water in the seas to expand (like mercury rising in a thermometer), with a consequential rise in sea level. Some melting of ice will also contribute to rises in the water level: ice that is currently piled up on land (in Antarctica and in Greenland, say) would add to the height of the sea; melting of floating ice would not (Yearley, 2008, 78).

In a changed world, these factors would no longer be true and many coastal (or estuarine) cities would be in danger of periodic flooding, possibly inundation: New York, London, Amsterdam, Lisbon, Rio de Janeiro, Melbourne, Cape Town. These changes will impact on natural systems too. For example, if the Arctic ice melts completely in summer, polar bears will lose their customary habitat; they may have literally nowhere to go. Other animals may be able to move toward the poles (or to higher altitudes) to stay within their natural habitat zones, but plants may not be able to move quickly enough to cope with the change; it is feared that forests will suffer particularly and this would clearly be bad news for the birds, insects, and animals that live in forests.

Consequences of Global Warming

Although the geophysical and atmospheric drivers of global warming have been known ...