1. The threat of climate change


Climate Change and Biodiversity Conservation



The threat of climate change is real. Atmospheric scientists agree that without urgent measures to control carbon dioxide and other greenhouse gas emissions, the global climate will be rapidly and radically changed. The consequences will be dire for wildlife and natural ecosystems, with sea­level rise, increased risk of fire and storm, changed rainfall patterns, and trends towards warming and aridity all taking their toll. National Parks and endangered species will be in the front line of the climate assault, and delicate ecosystems such as coral reefs, alpine meadows, and temperate rainforests may undergo damaging and irreversible changes.


WWF's mission is the preservation of biodiversity and natural ecosystems. Therefore we consider solving the climate change problem as one of the most critical environmental challenges of the coming decades. Achievement of a solution that results in reduced emissions of greenhouse gases will depend on the successful implementation and strengthening of the new UN climate treaty.




National parks and endangered species will be in the front line of the climate assault



Nations that are Parties to the UN Framework Convention on Climate Change (UNFCCC) are committed to the ultimate objective of "...stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change...". Current greenhouse gas concentrations are already likely to pose serious risks to some species and ecosystems. Carbon dioxide (CO2) concentrations are 25 per cent above pre­industrial levels, and rising, while methane (CH4) concentrations have doubled since the industrial revolution. Recent severe storms, droughts, floods, and forest fires, although they cannot unambiguously be linked to climate change, give an indication of the impacts that could result from human interference with the climate system, even at current greenhouse gas concentrations.




Storms and hurricanes may become more frequent, along with severe droughts and floods



Climatic changes during the quaternary period (the last two million years), which was characterized by glacial ice ages and warmer interglacial periods, caused major alterations in biomes and ecosystems across Europe and North America. Yet very few species became extinct during this period, other than those restricted to islands or mountain ranges, because the populations of plants and animals were able to migrate according to the changing climatic conditions. But now the situation is very different for two reasons. First, the rate of climate change may be unprecedented, and organisms will not be able to adapt or migrate fast enough. Second, natural habitats are now patchy and isolated, like islands in a developed landscape, and plants and animals are often blocked from successful migration.


Evidence suggests that the climate may have already begun to change. According to historical temperature records, the 1980s was the warmest decade on record, and 1994 the third or fourth warmest year since reliable measurements began in 1850. Examination of annual growth rings from one of the world's oldest trees in Tasmania show that the last three decades were the warmest in the region for 2000 years. Some of the strongest supporting evidence for the existence of a warming trend during the last 100 years comes from analyses showing that most of the world's mountain glaciers are shrinking and that snow cover is decreasing too. In the European Alps, glaciers are melting twice as fast as they did at the end of the last ice age. Photographic records from the Venezuelan Andes show that the present day snowline is 600m higher than it was in 1885. Further indications of the warming trend come from research into the underlying cause of the desertification that has taken a grip in the Sahelian countries of sub­Saharan Africa. The Sahel is in the grip of a 25­year period of low rainfall and desiccation at least as severe as anything seen during the last 1,000 years.




WWF is working on a scientific assessment of the impacts on wildlife and ecosystems

Although we cannot yet conclusively prove that changes such as these are caused by man­made greenhouse gas emissions, they are consistent with predictions made by powerful computer models called global circulation models. These predict that global warming of approximately 0.3°C per decade can be expected during the next century. However, this warming will not be evenly spread over the globe; the biggest changes are expected at higher latitudes. Warming will most likely be accompanied by sea­level rise of approximately 6 cm per decade. ( a )

( b )

As well as the changes in temperature and sea­level, there is major concern about increased variability of weather patterns. Storms and hurricanes may become more frequent, severe and widespread, rainfall patterns will change, and the likelihood of many countries experiencing severe droughts and floods will increase. The number of people living in low­lying coastal areas and subject to annual flooding could double to nearly 100 million by the year 2020. On land, many scientists predict that increases in droughts and storms will radically increase the risk of wildfires in temperate and boreal forests. The costs of these disasters will fall most heavily on the nations least able to afford them.



Evidence of the rising level of CO2 in the atmosphere since the Industrial Revolution comes from (a) Antarctic ice samples and (b) theMauna Loa Observatory, Hawaii.



Back to the previous page
Back to Publications & Research

Copyright 1996, The World Wide Fund For Nature