Climate change

What is global warming?

Scientists have understood since the 19th century that the earth’s climate might be changed by an increasing concentration of carbon dioxide in the atmosphere. Carbon dioxide, and similar gases, trap infra red radiation on earth that would otherwise dissipate into space. This is known as the “greenhouse effect” and the gases as “greenhouse gases”. As burning fossil fuels such as oil, coal and gas - on which modern economies rely - produces carbon dioxide in large quantities, this colourless, odourless and otherwise harmless gas has been identified as potentially dangerous to the environment.

What are the effects of climate change?

A little heating of the earth might not sound very dangerous. However, scientists now understand that heating the earth has other effects too. An increase in extreme weather, such as storms, droughts, floods and heatwaves can also result. Some areas grow drier, turning into deserts, while others grow wetter. Ice in the Arctic and Antarctic and glaciers on mountain tops may also melt, and this could push up the sea level. There is also a small risk of very extreme events: for instance, some scientists have posited that the Gulf Stream weather system that warms Europe could change direction under the influence of melting ice from the Arctic, which would have a drastic effect on Europe’s weather.

What do scientists say we need to do to stop climate change?

Reduce our emissions of carbon dioxide, and other greenhouse gases, into the atmosphere. This can be achieved by various means: using alternative energy sources, such as the wind, sun and tide; powering vehicles using electricity, hydrogen or ethanol, which is derived from plants that take up carbon dioxide from the atmosphere as they grow; capturing and storing carbon dioxide as it is emitted from power stations; using our energy more efficiently, for instance by insulating our houses better and turning off electrical devices when they are not in use.

What is the Kyoto protocol?

It is an international treaty, brokered by the United Nations, which binds developed nations to reduce their emissions of six greenhouse gases by about 5 per cent relative to 1990 levels by 2012. The US and Australia are the only developed countries to have refused to ratify the treaty. The US has argued that the treaty is unfair, because it does not require developing nations to cut their greenhouse gas emissions. The US has also expressed reservations over climate change science: President George W Bush and some of his advisors have indicated that more scientific research needs to be done in order to establish whether climate change is real.

What do the scientists say?

Most climate change scientists say the evidence showing climate change is happening is already compelling. In June, the national science academies of all of the G8 nations, accompanied by the national science academies of China, India and Brazil, took the unprecedented step of issuing a joint statement to the political leaders of the G8. This statement affirmed that the scientific case for climate change had been made and there was “strong evidence that significant global warming is occurring”. The scientists asked G8 leaders to “identify cost-effective steps that they can take now, to contribute to substantial and long-term reduction in net global greenhouse gas emissions”.

Why is the US out of step with the other major industrialised nations on the need to tackle climate change?

The US opposes the Kyoto protocol on grounds of economic unfairness, because developing nations are not included in its provisions. However, the US has also expressed doubts over climate change science. Within the ruling Republican party in the US, there are many “climate change sceptics”. These are people who disagree with mainstream scientific thinking that climate change caused by human action exists and is a problem. While scientists who take such views are in a minority, their cause has been championed by many politicians who believe that cutting greenhouse gas emissions would involve unacceptable economic costs.

Climate timeline

1988: United Nations forms the Intergovernmental Panel on Climate Change to study the problem

1992: Rio Earth Summit discusses climate change and other pressing environmental concerns

1997: Kyoto Protocol signed, binding developed countries to cut their emissions of greenhouse gases by at least 5 per cent relative to 1990 levels by 2012. Signatories begin the process of ratifying the protocol, which must be accepted by developed nations emitting more than 55 per cent of the world’s greenhouse gases to come into effect.

2000: George W. Bush as a presidential candidate signals he will take action on climate change if elected

2001: President Bush casts doubt on the scientific evidence supporting climate change

2004: Under pressure from the EU, Russia ratifies the Kyoto protocol. Ratifications have now passed the threshold stipulated in the treaty.

January 1: 2005 EU’s emissions trading scheme begins

February 16: 2005 Kyoto protocol enters into effect

July 6-8 2005: G8 meeting at Gleneagles reaches agreement on climate change

November 28 – December 9 2005: Parties to the Kyoto protocol meet in Montreal, Canada, to discuss the future of the treaty

2012: Provisions of the Kyoto protocol expire

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