What is climate change?

ORIGINS OF CLIMATE CHANGE AND URGENCY OF THE ISSUE

The greenhouse effect is a natural warming process. Carbon dioxide and certain other gases – called greenhouse gases - create a warming effect that has some similarity to the warming inside a greenhouse. Human activity - particularly the burning of fossil fuels - has enhanced the effect by thickening the blanket of greenhouse gases around the earth. Global greenhouse gases (GHG) emissions from human activities have grown since pre-industrial times, with an increase of 70% between 1975 and 2004. Industrial nations have a historical responsibility in this increase.

According to the Intergovernmental Panel on Climate Change (IPCC), a CO2 concentration of 350ppm (parts per million) is the maximum concentration in the atmosphere that the world can support to avoid the worst of global climate change and maintain the temperature rise below 2 degrees. Now, we are at about 393 ppm (Mauna Loa Observatory, July 2011) and this figure is still climbing.

With current climate change mitigation policies and related sustainable development practices, global GHG emissions will continue to grow over the next few decades. The clock is ticking; we are the generation that determines the future of the world’s climate.

THE IMPACTS OF CLIMATE CHANGE

The increase in global temperatures is altering the complex web of systems that allow life to thrive on earth, such as cloud cover, rainfall, wind patterns, ocean currents, and the distribution of species. This causes important consequences, including severe biodiversity losses.

According to the IPCC, if global average temperature rises by 2 degrees C (3.6 degrees F), rising sea levels and melting snow and ice across the globe could submerge several small island states and Bangladesh.

Global climate change will contribute to more drastic and severe weather around the world. This includes more heat waves; a significant increase in the number of heavy precipitations events; and an increase in the number of tropical cyclones.

Climate change is also exacerbating water shortages in many areas, constraining agricultural production and threatening food security, causing forest fires and degradation, damaging coastal and marine resources, and increasing the risk of outbreaks of infectious diseases.

Southeast Asia has already experienced a an increased frequency and intensity of extreme weather events such as heat waves, droughts, floods, and tropical cyclones in recent decades, as well as more water shortages. The region is projected to suffer more from climate change than many other regions: extreme weather events; declining crop yields; loss of forests; damage to coastal resources; increased outbreaks of diseases; and associated economic losses and human suffering (source: The Economics of Climate Change in Southeast Asia, ADB, 2009).


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