It is now evident that Earth’s climate is warming. According to the UN Intergovernmental Panel on Climate Change (IPCC), by 2005, the average global temperature was 0.76°C above the pre-industrial times level. The average temperature is rising by almost 0.2°C every ten years. This man-made warming is causing a number of climatic and environmental changes.
Image: Courtesy of Greenpeace Greece
Glaciers of the Alps, Rockies, Andes, Himalayas, Africa and Alaska are retreating. The melting of glaciers is putting millions of people at risk of floods and will eventually deprive them of fresh water resources. Ice glaciers deflect almost 80% of the heat from the sun and absorb about 20% of the heat. When an ice glacier vanishes and exposes the earth below, 80% of the heat from the sun is absorbed by the earth, and only about 20% of this heat is deflected back.
Global warming has caused the melting of parts of the ice caps. In recent decades, the area of sea covered by the Arctic ice at the North Pole has shrunk by 10% while the thickness of the ice above the water has decreased by about 40%. Since 1970, Arctic sea-ice has been declining, reducing by 0.6 million km² per decade. At the same time, on the other side of the world, the ice sheet above the Antarctic continent has become increasingly unstable.
Photo Credits: Theofanis Karafotias
Sea-level rise is a key marine impact of climate change and will have a substantial effect on the world’s coastal infrastructure, communities and ecosystems. Since 1900 sea levels have risen on average, by about 17 cm globally. The mean sea-level &extreme sea-level are two aspects of sea level that could face changes under global warming. The 2 main mechanisms which give increases in the global average sea level are thermal expansion of the warming oceans,&addition of water.
Image: Angie Bugeja
Floods, droughts, storms and heat-waves are becoming more severe and more frequent. The impacts of these events include water availability and crop yields as well as the impact on human health. The 2003 heat-wave in southern Europe contributed to the deaths of at least 22.146 people and triggered large-scale forest fires. The average number of weather and climate-related disasters per year in Europe increased by about 65% between 1998&2007 compared to 1980’s average.
Climate change-caused heat-waves can have direct impact on human health. Global warming can increase the spread of tropical diseases. Areas suitable for mosquitoes, ticks and sand flies carrying malaria and dengue will expand and these diseases will become more common. The tiger mosquito, which can transmit a variety of diseases, has extended its area in Europe considerably over the past 15 years. By 2000, according to WHO more than 150.000 died due to climate change.
Image: Greenpeace Greece
If the global average temperature increases by more than 1.5-2.5°C above 1980-1999 levels, some of 20 to 30% of plant and animal species may be at increased risk of extinction. Because of global warming coral reefs are already suffering extensive damage. Polar mammals and birds, such as polar bears, seals and penguins are especially vulnerable. “Healthy ecosystems are essential in any strategy for climate change adaptation. One can say that conservation of biodiversCourtesy of Greenpeace Greece
Climate change could threaten regional and international security by triggering conflicts, famines and refugee movements, through its impact on water and food supply. Worldwide, up to 1 billion ‘climate change refugees’ could be driven from their homes. Events associated with climate change that may create refugees include shoreline erosion, coastal flooding and agricultural disruption.
Photo Credits: Sergios Soursos
With the existing climate change scenario, almost half the world’s population will be living in areas of high water stress by 2030, including between 75 million & 250 million people in Africa. In addition, water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people. That means if global temperature increase by 2.5°C above pre-industrial level an additional 2.4 to 3.1 billion people worldwide are likely to suffer from water scarcity.