Links to
other
pages
BACK TO CLIMATE CHANGE
MAIN PAGE
THE IMPACTS
OF GLOBAL WARMING
INERTIA: LEADERS FAILING TO ACT
WATER:WORLD
IS
IN CRISIS
MILLIONS MADE INTO REFUGEES
EL NIÑO: THREAT FROM THE OCEAN
SUSTAINABLE LIVING
MAIN PAGE
Diverse ecosystems are essential to human life
Biodiversity is the term used to describe the diversity of life-forms on Earth and their distribution across the landscape.
It includes plants, animals and micro-organisms, the genes they contain, and the range of ecosystems they form, including terrestrial, marine and freshwater environments.
All life forms are interconnected, and the preservation of Earth's biodiversity is essential to the survival of human life.
The maintenance of biodiversity relates to the sustainable use and management of biological resources such as land, air and water, to ensure that the Earth’s life support systems are maintained and enhanced for today’s and future generations.
Our Food depends on it - one of the great benefits of protecting biodiversity is that it provides a pool of genes to improve our crops.
Wild genes can provide resistance to disease, improve production and protect against long-term changes in temperatures and rainfall. Everything we eat has a genetic tradition.
Our Medicines are made from it – more than 21,000 plants have medical uses.
Examples of life support systems and essential ecological services provided by biodiversity include oxygen production, climate control, carbon sequestration, soil formation and stabilisation, water purification, pest control, disposal of wastes and nutrient cycling.
A diversity of species increases the ability of ecosystems to do things like hold soils together, maintain soil fertility, deliver clean water to streams and rivers, cycle nutrients, pollinate plants (including crops), and buffer against pests and diseases.
A loss of species could reduce this ability, particularly if environmental conditions are changing rapidly at the same time.
It is therefore possible that as the climate changes and as species are eliminated from an area there will be changes in some ecosystem functions; this could mean more land degradation, changes in agricultural productivity, and a reduction in the quality of water delivered to human populations.
As global warming interacts with other factors such as habitat-destruction, invasive species, and the build up of carbon dioxide in the landscape, the risk of extinction increases.
As the climate warms, some species will need to migrate to cooler and moister environments, usually uphill or southwards in the southern hemisphere.
There is some evidence that plants and animals are already responding to warmer temperatures. The treeline (above which there are no trees) near Mount Hotham in the Victorian Alps has reportedly moved up in altitude by 40 metres in recent years.
In many cases, however, such migration might not be possible because of unsuitable soils and other unfavourable environmental parameters, geographical or human-made barriers and competition from species already in an area.
As human activities, particularly agriculture but also settlement and industrial development, have expanded over the last few centuries, natural vegetation – such as forests, grasslands and heathlands – has been cleared in large swathes.
Once-extensive plant communities have been reduced in size and broken into smaller patches. This habitat reduction and fragmentation poses a problem because it limits the ability of many species to migrate to more favourable conditions.
Predicted changes in the intensity, frequency and extent of disturbances such as fire, cyclone, drought and flood will place existing vegetation under greater stress and favour species able to rapidly colonise denuded areas.
In many cases this will mean the spread of 'weed' species and major changes in the distribution and abundance of many indigenous species.
Some of the impacts of global warming may be sudden, but in many cases societies will have some years to adapt their management of biodiversity as conditions change.
Increasing our understanding of the effects of climate change on biodiversity, and developing practical ways of mitigating such effects, are critical to limit the damage.
Even so, the dangers are great – for humans as well as our native plants and animals.
Back to the age of the dinosaurs Not only will carbon dioxide levels be at the highest levels for 24 million years, but global average temperatures will be higher than for up to 10 million years. "If the most extreme warming predicted takes place we will be going back to global temperatures not seen since the age of the dinosaur." Scientists say 80 percent of species have already begun moving their traditional territorial ranges in response to the changing climatic conditions. Not only have the animals, birds and insects started to react, but there is evidence vegetation is also on the move. •Fact •Fact |