Global warming is caused by increasing the intensity of the greenhouse effect, which is the process by which the Earth’s atmosphere traps some of the Sun’s energy, warming the Earth enough to support life.
Humans contribute to the greenhouse effect through by burning fossil fuels and deforestation. These actions are amplified by a rising population, higher living standards and positive feedbacks that re-circulate the impacts of our greenhouse emissions.
In addition to our contributions, some natural processes also affect the climate. Volcanic eruptions, orbital tilting of the Earth and flares from the sun all alter global temperatures. However, while these factors affect the natural variability of the climate, human contributions have unbalanced the Earth’s natural processes.
It is now quite clear that the fossil fuels that we have used to power the rise of our industrial civilisations have caused unprecedented amounts of carbon dioxide and other greenhouse gases to infiltrate the atmosphere.
At the same time, we have felled half of our forests to build towns and clear land for food production needed to satiate the needs of a rising population with increasingly unsustainable consumption.
By cutting down our trees, which supply oxygen to support life, we are removing one of the primary carbon absorbing bodies that could offset our emissions from burning fossil fuels. Global warming dries out forests, killing trees and releasing more carbon into the atmosphere, changing carbon sinks into carbon sources.
With more and more humans demanding resources for their basic needs, fossil fuels are burnt at increasing rates to generate enough energy for our rising population. More and more forests are burnt and felled to create timber and land for our survival. In 2008, carbon dioxide emissions from fossil fuel burning, building construction and deforestation were 24% higher than in 1990.
Simultaneously, the need for real action on climate change is growing increasingly urgent, as positive feedbacks multiply the effects of our actions to the point where the damage may be irreversible.
To change the course of the last three hundred years, we need to take radical action now to prevent runaway climate change.
Not only do we need to stop burning fossil fuels and cutting down forests, we need to look to positive solutions to remove the carbon already in the atmosphere.
San Diego State University, Department of Geological Sciences, ‘Climate effects of volcanic eruptions’, http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html
Ron Nielsen, ‘The Little Green Handbook: Seven Trends Shaping the Future of Our Planet’, 2006, Picador, New York
Ian Ammison, et. al., 2011, ‘The Copenhagen Diagnosis: Updating the world on the latest climate science’, p. 22.
Ian Ammison, et. al., 2011, ‘The Copenhagen Diagnosis: Updating the world on the latest climate science’, p. 1.