Causes of Climate Change | WWF New Zealand

Causes of Climate Change



 
	© James Frankham / WWF
Burning flare stacks in Atacapi Station, an oil field in the Amazon rainforest, Ecuador. The buring of fossil fuels like oil and gas, and deforestation by humans contribute to climate change
© James Frankham / WWF
Climate change is occurring because of human activities that release excessive amounts of greenhouse gases into the atmosphere.
These greenhouse gases – such as carbon dioxide, methane and nitrous oxide – warm the air by trapping heat that radiates from the Earth’s surface. Over the last 200 years, concentrations of these gases in the Earth’s atmosphere have increased.

Temperatures are increasing

As concentrations of greenhouse gases have increased, the Earth has warmed. During the past century, the average global temperature has risen by 0.74ºC, with most of that occurring since 1970.  At the poles, many areas are warming at a rate two or three times the global average.


The main causes of climate change

  • Humanity’s increased use of fossil fuels – such as coal, oil and gas to generate electricity, run cars and other forms of transport, and power manufacturing and industry
  • Deforestation - because living trees absorb and store carbon dioxide
  • Increasingly intensive agriculture - which emits methane and nitrous oxide.
Today's industrialised countries - includng New Zealand - have built their economies on buring fossil fuels to provide electricity, transport and to develop industries. Developing countries are now beginning to do the same.

Tipping Points

What makes climate change so urgent is that temperatures will continue to increase long after greenhouse gas emissions are curbed. Scientists believe the planet may reach a ‘tipping point’ at which time changes will become irreversible, such as the melting of ice sheets, which will drastically effect both sea levels and the planet's entire climate system.

The Consensus on Climate Change

Climate scientists believe that human-made greenhouse gas emissions are responsible for the vast majority of global warming.
The Intergovernmental Panel on Climate Change, the United Nations Environment Program’s climate body, has said for over a decade that there is “unequivocal” evidence that the planet is warming and that the temperature increase is “very likely” due to human-made greenhouse gas emissions.

The IPCC does not carry out research itself but bases its assessment on peer reviewed and published scientific/technical literature.

The panel is made up of:
  • 2500+ scientific expert reviewers
  • 800+ contributing authors
  • 450+ lead authors
  • from 130+ countries