Climate Change

CLIMATE CHANGE

Most scientists now agree that human-induced global climate change poses a serious threat to both society and the Earth's ecosystems. But what is climate change? How will it affect developing countries? And what can be done to reduce the threats it poses?
Gases including carbon dioxide, nitrous oxide, methane and water vapour trap heat from the sun within the atmosphere. Acting like the panes of glass in a greenhouse, they ensure that temperatures close to the Earth's surface are much warmer than they would otherwise be. In this way, the greenhouse effect makes life as we know it possible.
But this system has recently come under heavy pressure. Since the Industrial Revolution, humankind has been extracting and burning fossil fuels at increasing rates, releasing significant amounts of greenhouse gases into the atmosphere. As concentrations of greenhouse gases have increased, so has the strength of the greenhouse effect.
Scientists around the world are using computer models to try to predict how global climate is likely to be affected by this enhanced greenhouse effect in the years ahead. An important part of their work is producing scenarios of what the future climate may look like, based on a combination of past and current observations, and predicted levels of future emissions.
Since the early 1980s, this research has led to the conclusion that current trends in climate change are likely to cause an increasing number of threats to the natural world and to human societies. Since 1988, governments have delegated the task of reaching a scientific consensus on climate change to the Intergovernmental Panel on Climate Change (IPCC).
Its third and most recent assessment, published in 2001, suggests that "there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities". The report also states that average global temperatures are projected to increase by 1.4 to 5.8 degrees Celsius over the next 100 years because of the enhanced greenhouse effect.

Due to this warming, glaciers and the polar ice caps are expected to melt, causing sea levels to rise by between nine and 88 centimetres in the coming century. The IPCC also expects significant changes to patterns of rainfall — including monsoons — and more extreme weather events.
These potential effects highlight the need for a coordinated and scientifically based international response.
The international response
International action to tackle climate change has been steadily increasing since the early 1990s, a reflection of warnings from the scientific community. In 1992, an agreement was reached at the UN Conference on Environment and Development, held in Rio de Janeiro, Brazil, on the text of the UN Framework Convention on Climate Change.
This agreement, which has so far been ratified by 188 countries, aims to reduce emissions to levels that "prevent dangerous interference with the climate system". It is not, however, a legally binding instrument. With concern about climate change growing throughout the 1990s, the text of an additional 'protocol', intended to serve as a legally binding instrument to help meet the convention's objective, was negotiated in Kyoto, Japan, in 1997.
The target of what has become known as the 'Kyoto Protocol' is that industrialised countries — called 'Annex I' countries — should reduce emissions of greenhouse gases to at least five per cent below their average 1990 levels by 2012. They can meet this target by reducing emissions of greenhouse gases directly or by creating carbon 'sinks' that absorb carbon dioxide from the atmosphere (for example by planting forests).
The protocol also includes three international mechanisms, called flexible mechanisms, which aim to make it cheaper to reach the Kyoto Protocol's targets of reducing greenhouse gas emissions in industrialised countries.
Two of these mechanisms are intended to promote investment either in developing countries (through the Clean Development Mechanism), or in countries undergoing the transition to a market economy (through Joint Implementation). The third mechanism, known as emission trading, allows one country to 'sell' parts of its emission quota to another, a move intended to maximise cost-efficiency in emission reduction strategies.
After seven years of difficult negotiations, the protocol entered into force on 16 February 2005, having been ratified by 141 countries. Together, the 141 nations account for 61.6 per cent of global carbon dioxide emissions. The agreement is thus now binding international law.
The protocol's 2012 target is seen as an initial step by many scientists and policy makers, and after 2012, a second commitment period would come into effect. The terms of 'post 2012', sometimes referred to as 'post Kyoto', are the subject of on-going negotiations. Contentious points include the roles of the United States, which has repeatedly refused to ratify the Kyoto Protocol, and of Brazil, China and India, three developing nations that are not bound to any reduction commitments but whose emissions compete with levels in developed nations.
The need to adapt to 'inevitable' climate change

Responses to global climate change cannot be limited to efforts of mitigation (reducing greenhouse gas emissions), as even the successful implementation of the most ambitious mitigation plan would not be sufficient to prevent continued global warming, at least not in the short term. We are already committed to some degree of climate change.
As a result, there has been growing recognition over the past decade that the severity of the likely impacts of climate change demands that we learn to adapt to them as well.
At the local level, adaptation is a process that takes place continuously in response to changes in the local environment. But in a climate change context, it can also refer to broader decisions, such as planting different crop varieties in drier years, building dams to protect communities from flooding, or protecting particularly vulnerable natural ecosystems that are a source of livelihoods.
Adaptation is already being discussed in policy circles, and is addressed in both the Kyoto Protocol and the Framework Convention. It has particular relevance to the challenge of achieving sustainable development, especially in developing countries as these are frequently the most vulnerable to the impacts of climate change. The main challenge is to work out what can be done in practical terms to reduce this vulnerability in the South.
Climate change and development
By their nature, the problems created by climate change cut into the core of economic activities in fields such as transport, energy, public health, agriculture and forestry. In addition, policies linked to both reducing greenhouse gases and adapting to the impacts of climate change are closely linked to broader development issues.
The stakes are high. The risks posed both by extreme weather events and systemic changes to our reliance on fossil fuels are significant. For developing countries, the story is further complicated by a lack of financial, social and institutional resources needed to face the threat of climate change. Although the challenges faced by the South in coming to terms with the impacts of climate change are slowly being acknowledged in international policy circles, policies to address these challenges effectively have yet to be designed and implemented.
Central to this task is the need to encourage proactive choices by all those concerned about the impacts of climate change on the developing world. This dossier aims to help achieve this by offering a set of online resources that provide the knowledge base needed to address these problems.
It includes recent news and feature articles on issues relating to the science and politics of climate change, policy briefs analysing key issues and describing their importance, selected opinion articles from stakeholders in the climate change debate, and key documents covering the spectrum between climate change science and development needs.
By presenting this information in an accessible, focused yet comprehensive form, we hope that this dossier will enable policymakers, scientists, educators and others to make informed choices about climate change and the challenges it presents humankind.

http://www.scidev.net/dossiers/index.cfm?fuseaction=dossierfulltext&Dossier=4

by Xavier Quiroz ortiz