Selasa, 04 Oktober 2011

The effects of global warming

The effects of global warming in the 21st century and beyond are expected to be disastrous, according to the summary of a scientific report issued on April 6, 2007 by the world’s leading panel of climate change scientists. And many of those changes are already under way. Global Warming to Affect Every Person on Earth
Climate Change 2007: Impacts, Adaptation and Vulnerability [pdf], the report from Working Group II of the United Nations’ Intergovernmental Panel on Climate Change (IPCC)—which took six years to compile and draws on the research of 2,500 scientists from more than 130 countries—also makes it clear that while poor people worldwide will suffer most from the effects of global warming, no person on Earth will escape its consequences. The effects of global warming will be felt in every region and at all levels of society.
“It’s the poorest of the poor in the world — and this includes poor people even in prosperous societies — who are going to be the worst hit,” said Rajendra K Pachauri, the chairman of the panel and an energy expert from India. “People who are poor are least equipped to be able to adapt to the impacts of climate change, and therefore, in some sense, this does become a global responsibility, in my view.”
The summary report on the effects of global warming is part two of a four-part IPCC report that will be released in stages throughout 2007. The first part, released in February 2007, confirmed with 90 percent certainty that global warming is now unstoppable and humans are to blame for a significant portion of the heat-trapping greenhouse gases that have caused global temperatures to rise dramatically since the middle of the 20th century.
Urgent Action is Needed to Reduce Global Warming
Rising global temperatures may bring some temporary benefits, according to the report, most notably increased food production due to more rainfall and longer growing seasons at mid-to-high latitudes and fewer deaths associated with cold weather. But scientists expect these short-term benefits to be outweighed by increased drought, flooding, water scarcity and hunger in other regions as well as more death and disease worldwide.
“It is now clear that we are to blame for the last 50 years of warming, and this is already causing adverse changes to our planet,” said Catherine Pearce, climate campaigner for Friends of the Earth International. “Unless we take action to reduce emissions now, far worse is yet to come, condemning millions in the poorest parts of the world to loss of lives, livelihoods and homes. Climate change is no longer just an environmental issue. It is a looming humanitarian catastrophe, threatening ultimately our global security and survival.”
Findings of the report include:

  • Projected climate change is likely to affect millions of people who are already vulnerable. Heat waves, floods, storms, fires and droughts will cause increased death, disease and other harm. Global warming is also expected to lead to more deaths due to malnutrition, diseases that cause diarrhea, cardio-respiratory diseases related to higher concentrations of ground-level ozone, and wider distribution of diseases carried by insects, rodents, etc.
  • Millions more people are projected to be at risk from coastal flooding due to sea level rise, especially in densely populated and low-lying settlements that already face other challenges, such as hurricanes and tropical storms.
  • Approximately 20-30 percent of plant and animal species assessed so far are likely to be at higher risk of extinction if increases in global average temperature exceed 1.5-2.5 degrees Celsius. The global average temperature already has increased by about 0.74 degrees Celsius over pre-industrial levels.
  • In the course of the current century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability in regions supplied by meltwater from major mountain ranges, where more than one-sixth of the world population currently lives. For example, glacial retreat in the Himalayas will disrupt downstream water supplies, which will have implications for billions of people across India, China, Nepal and Bhutan.
  • By 2020, 75-250 million people in Africa will be exposed to water scarcity due to climate change.
  • During the same period, yields from rain-fed agriculture in some African countries could be reduced by 50 percent.
  • Latin America faces a risk of significant biodiversity loss by mid-century as increases in temperature and associated decreases in soil water lead to gradual replacement of tropical forest with savanna in parts of the Amazon region.
  • People living on small islands, such as those found in the Caribbean and the Pacific, are particularly vulnerable to rising sea levels, extreme weather, and deteriorating coastal conditions associated with global warming. Climate change is projected to reduce water resources on many small islands and to adversely affect the livelihoods of island communities by undermining fisheries, tourism and other core components of island economies.
Diplomats Overrule Scientists on Certainty of Global Warming Effects
If these warnings seem dire, consider that the language was softened just hours before the report was released, a political maneuver led by China and Saudi Arabia that brought sharp protests from some of the leading scientists who worked on the report

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