Focus On Climate Change
Climate Change
What is Climate Change?
The climate of the Earth is constantly changing, something which in the past was a result of natural causes. Nowadays, the term climate change is mainly used when referring to changes in our climate which generally are a result of human activity. According to the recently released Intergovernmental Panel on Climate Change's (IPCC) report of Working Group I, Climate Change 2007: The Scientific Basis, during the 20th century the global average temperature has been rising by 0.74oC. In the Northern Hemisphere in particular, this is greater than any temperature changes that have occured in the last 1000 years.
Direct Observations of Recent Climate Change. Courtesy of IPCC. Click on image to see larger version.
What are the effects of climate change?
Iceberg Lancaster Sound, courtesy of H. Oerter
Changes in climate affects both physical and biological systems. The IPCC reports also found that regional changes in temperature in particular have already affected many parts of the world. For example, increased temperatures cause shrinking glaciers, thawing permafrost, later freezing and earlier break-up of ice on rivers and lakes, lengthening of mid- to high-latitude growing seasons, poleward and altitudinal shifts of plant and animal ranges, decline of some plant and animal populations, and earlier flowering of trees, emergence of insects, and egg-laying in birds. These kind of changes have been documented in both aquatic, terrestrial and marine environments.
It is clear that the changing climate is an issue worthy of large research efforts. ESF is spear heading a number of research initiatives related to Climate Change.
Human activities as the main drivers of the recently observed global warming. Courtesy of IPCC. Click on image to see larger version.
Human and activities are the drivers of the recently observed Climate Change
Carbon dioxicide (CO2), methane (CH4) and natrious oxide (N2O) Concentrations
- far exceed pre-industrial values
- increased markedly since 1750 due to human activities
The global atmospheric concentration of carbon dioxide has increased from a pre-industrial value of about 280 ppm to 379 ppm. The atmospheric concentration of carbon dioxide in 2005 exceeds by far the natural range over the last 650,000 years (180 to 300 ppm) as determined from ice cores. The annual carbon dioxide concentration growth rate was larger during the last 10 years (1995–2005 average: 1.9 ppm per year), than it has been since the beginning of continuous direct atmospheric measurements (1960–2005 average: 1.4 ppm per year).
Projections of future changes in climate
Projections of future changes in global mean temperature. Courtesy of IPCC. Click on image to see larger version.
The best estimate of global surface temperature increase of the 21st century ranges from 1.8°C (likely range is 1.1°C to 2.9°C) for the low scenario of CO2 emission (B1) to 4.0°C (likely range is 2.4°C to 6.4°C) for high CO2emission (A1FI).
These results obtained by the IPCC (2007) have been retained by a series of coupled atmosphere-ocean numerical model simulations.
ESF and Climate Change Research
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