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• Today’s atmosphere contains about 40% more carbon dioxide than at the start of the industrial era. This build-up of carbon dioxide and other greenhouse gases prevents heat from leaving the earth’s surface and the increase in greenhouse gases is expected to trigger a rise in temperature of 1.4 - 5.8¡C by 2100.

• Worldwide, seven out of ten of the warmest years since 1860 occurred in the 1990s and 1998 was the warmest year on record. By the end of the 20th century, global temperatures were 0.6°C higher than 100 years ago. In central England, 1999 was the warmest year since 1659 and 1990 was the second warmest year. Analysis of tree rings, ice cores, corals and historical records indicate that the 1990s were the warmest decade of the last millennium.

• Stabilising greenhouse gas concentrations in the atmosphere at current levels requires emissions reductions of about 70% by the end of this century at the latest. Even if the Kyoto Protocol were ratified and fully implemented it could not moderate the expected warming trend of 1.4° C by 2050 by more than 0.05°C

• Carbon sink activities may well develop into future carbon bombs once climate change reduces the ability of trees to survive in their current locations: A recent study on the implications of a doubling of carbon dioxide levels in the atmosphere concluded that forest dieback, mostly in boreal forest, could release 70 to 130 billion tones of additional carbon into the atmosphere. Another study found that such a carbon pulse triggered by warmer temperatures in the boreal region could release as much as 225 billion tonnes of carbon – almost one third of all the carbon now in the Earth’s atmosphere.
Jardin K (1994). The Carbon Bomb. p.25

• Unusually large outbreaks of the tree-eating insect, the spruce budworm, have devastated large areas in the boreal forests in Canada in recent years. A government study released in 1987 showed that conifers were growing on average up to 65 percent slower than in the 1940 and 50s because of budworm outbreaks and possibly acid rain.
Jardin K (1994). The Carbon Bomb. p.14.

• The only truly effective way to tackle climate change is to reduce emissions. Paper substitutions of emission cuts with carbon sink credits allow governments to be distracted from this urgent but politically controversial task.

• To offset the emissions of a power plant the size of Drax (3.75GW) in the UK would require the establishment of 1 million hectares (10,000 km2) of new tropical forest. To offset the UK’s total carbon dioxide emissions would require the planting of a new area of tropical forest about 1.5 times the size of the UK.
UK DoE, 1991.

• Biological diversity will be threatened by rapid climate change: Observations, models and experiments demonstrate that a sustained increase of just 1°C in the global average temperature would affect the functioning and composition of forests. The species that make up today's forests may not be able to survive in their current locations as local climate conditions change beyond their tolerance levels. This could result in a major impact on the species composition of one third of the world's forests. Entire forest ecosystems may disappear, other stresses caused by global warming include more insect outbreaks and fires. Because high latitudes are expected to warm more than equatorial ones, boreal forests will be more affected than temperate and tropical forests.

• Forests are a major reservoir of carbon, containing some 80% of all carbon stored in land vegetation and about 40% of the carbon residing in soils. Large quantities of carbon may be released into the atmosphere during transition from one forest type to another as a result of global warming.

• Fire suppression is in part responsible for the increase in biomass documented in many European temperate and boreal forests. While fire suppression may enhance sequestration in the short term, it can also create tinderbox conditions that increase the risk of fire and subsequent release of large amounts of CO2 into the atmosphere (for details on forest fire trends in boreal forests, see The Carbon Bomb, Greenpeace International, Sept 1994, available from www.greenpeace.org).

• A study in Oregon found that a 450-year-old natural forest stored 2.2 to 2.3 times more carbon than a 60-year-old douglas fir plantation on a comparable site.
(Source: Harmon M., 1990, Effects on carbon storage of conversion of old-growth forests to young forests. Science 247, pg.699-702).

• Globally, vegetation contains 550+100 petagrams of carbon (PgC), soils contain a much larger amount, 1750+250 PgC. Together, soils and vegetation contain about three times as much carbon as the atmosphere. Most of the vegetation carbon is in forests, especially in the tropics, while most of the soil carbon occurs at northern high and temperate latitudes in both forests and grasslands. The ratio of soil carbon to vegetation carbon is about 5 in boreal forests, but less than 1 in most tropical forests.
(Source: The Royal Society, 2001, The role of land carbon sinks in mitigating global climate change. Royal Society Policy Document 10/01. July 2001.www.royalsoc.ac.uk.)