Perhaps no single environmental issue is as complex or holds such potentially profound implications for the world's inhabitants than global climate change.
There is little question that human activity is changing the make-up
of the atmosphere that surrounds our planet. As world economies have
become more industrialized over the last century, we have begun emitting
more greenhouse gases
into the air than natural processes can remove. Deforestation and clearing
land for agriculture have accelerated the buildup of greenhouse gases
in the atmosphere, both by releasing significant quantities of these
gases and by reducing the capacity of green plants to absorb carbon
dioxide, a chief greenhouse gas.Recent flooding in sub tropical cities
such as Noosa which until this recent
extreme downfall of rain had been sufffering a long drought and water
shortage shows the peril of ignoring climate change.
Climate change is the change in climate over a time period ranging from decades to centuries. The term refers to both natural and human-induced changes. Climate variability refers to shorter-term (from years to decades) fluctuations in climate, such as those caused by El Niño/Southern Oscillation.
The United Nations Framework Convention on Climate Change (FCCC) defines climate change as: "a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods." In other words, the FCCC uses the term climate change to mean only those changes that are brought about by human activities.
In 1995, a panel of more than 2,000 of the world's top climate scientists concluded that the Earth is indeed warming and that the "balance of evidence suggests a discernible human influence" on climate. Yet there are still large gaps in the scientific data. The warming in the last century -- about 0.5?C -- is still small enough to fall within the range of normal climatic changes for a planet that has fluctuated in and out of ice ages for at least the last 200,000 years. A small part of that half a degree of warming may have come from variations in the sun's intensity, which can raise or lower the Earth's temperatures in ways not yet fully understood.
Nevertheless, the bulk of recent evidence -- from rising sea levels and retreating glaciers to freak storms and floods -- appears to be falling within the boundaries of scientists' predictions of global warming. In December 1997, Canada and more than 150 nations gathered in Kyoto, Japan, to try to reach agreement on curbing the emissions implicated in global warming.
The global climate change issue will continue to be studied and debated for years into the future. Central to the debate are two fundamental questions:
Does the buildup of greenhouse gases in the atmosphere pose a threat to the world's citizens
If so, are there actions we can take that don't simply replace an ecological threat with an economic one?
In the 1980s, scientists began an intensive effort to answer the first question. In the 1990s, the world's scientific and political leaders have expanded their inquiries to encompass the second. Today's global climate change discussions focus not only on the science of the greenhouse gas effect but also on potential solutions.