The climate is changing. There is solid scientific evidence that the change is being caused in large part by human activity, and that it will have many serious and potentially damaging effects in the decades ahead. Greenhouse gas emissions from cars, power plants and other manmade sources—rather than natural variations in climate—are the primary cause.
Due largely to the combustion of fossil fuels, atmospheric concentrations of carbon dioxide (CO2), the principal greenhouse gas, are at a level unequaled for more than 400,000 years. As a result, an enhanced greenhouse effect is trapping more of the sun’s heat near the earth’s surface and gradually pushing the planet’s climate system into uncharted territory.
CO2 and other greenhouse gases have always been present in the atmosphere, keeping the earth hospitable to life by trapping heat. Since the industrial revolution, however, emissions of these gases from human activity have accumulated steadily, trapping more heat and amplifying the natural greenhouse effect.
As a result, global average temperatures have risen both on land and in the oceans, with observable impacts that foretell increasingly severe changes in the future. Polar ice is melting. Glaciers around the globe are in retreat. Storms are increasing in intensity. Ecosystems around the world are reacting, as plant and animal species struggle to adapt to a shifting climate and new climate-related threats emerge.
Newest previsions by the Intergovernmental Panel on Climate Change (in print 2012), a scientific body which collects research done in this field, points to a significantly enhanced risk of extreme weather events in many parts of the world, like extreme heat and extreme rainfall, due to greenhouse gas emissions. They have become more common since the 1950s, and it is foreseeable that these events, including hurricanes and flash floods, will be more frequent in the years to come. The International Energy Agency (IEA) released a similar report, warning that the world has five years before irreversible climate change happens.
In the developed world these changes will cause mostly economic damage, though lives will be lost. The peoples in the developing world, however, will suffer more due to their much higher vulnerability. Droughts and floods will impact food security significantly and will increasingly promote the spread of disease. Climate change will impact everyone globally but the intensity of its consequences depends on the capacity to cope with extreme events, and this capacity is greater in developed countries than in developing countries. On a positive note, the UN Environmental Program (UNEP) believes that cutting greenhouse gas emissions by 2020 is technologically and economically possible.
See UNDP Report, “Bridging the Emissions Gap” (2011)
written by Br. Bernd Beermann ofm cap