An introduction to climate change and global warming
Climate Change & Global Warming are the names given by scientists for the gradual increase in temperature of the Earth's surface
Over the past two decades the effect has become more marked. Considerable evidence exists that most of this warming has been caused by human activities... that's to say we have altered the chemical composition of the atmosphere through a buildup of greenhouse gases – primarily carbon dioxide, methane, and nitrous oxide.
What if we do nothing? Rising global temperatures will cause sea level to rise and alter local climate conditions, affecting forests, crop yields, and water supplies. It may also affect human health, animals, and many types of ecosystems. Deserts may expand and some of our countryside may be permanently altered.
What will happen in the future if we do nothing?
- Climate model simulations predict an increase in average surface air temperature of about 2.5°C by the year 2100 (Kattenberg et al., 1996).
- The likelihood of "killer" heat waves during the warm season will increase (Karl et al., 1997)
- The IPCC Second Assessment Report estimates that sea-levels will rise by approximately 49 cm over the next 100 years, with a range of uncertainty of 20-86 cm.
- Sea-level rise will lead to increased coastal flooding through direct inundation and an increase in the base for storm surges, allowing flooding of larger areas and higher elevations.
- Further melting of the Arctic Ice Caps (at the current rate) could be sufficient to turn off the ocean currents that drive the Gulf Stream, which keeps Britain up to 6°C warmer than it would otherwise be.
What can I do?
You have to go to work and we all like being consumers - but there are many ways you can help. Firstly, you need to recognise how you personally impact global warming. Carbon Footprint will show you how to minimise your impact - starting today - and show you how to make the right product choices in the future.
In February 2007, the IPCC (Intergovernmental Panel on Climate Change) issued its latest assessment report on climate change, which concluded that global warming is "unequivocal" and gave the strongest warning yet that it is very likely (> 90%) caused by human activities
The evidence for global warming and climate change includes the following:-
- Sea temperatures have risen by on average 0.5 degrees C (0.9 degree F) over the last 40 years [Tim Barnett, Scripps Institution of Oceanography in La Jolla, California]
- 20,000 square kilometers of fresh water ice melted in the Arctic between 1965 and 1995 [Ruth Curry, Woods Hole Oceanographic Institution in Connecticut]
- Worldwide measurements from tidal gauges indicate that global mean sea level has risen between 10 and 25 cm (18 cm average) during the last 100 years [Warrick et al., 1996]
- Global surface temperatures have risen about 0.7°C in the past 100 years [Met Office]
- 11 of the last 12 years rank amongst the 12 warmest years on record for global temperatures (since 1850) [IPCC, 2007]
- Since 1975, the increase of the 5-year mean temperature is about 0.5°C - a rate that is faster than for any previous period of equal length [NASA, 1999]
- Average annual temperature in the Arctic has increased by about 1° C over the last century -- a rate that is approximately double that of global average temperatures [IPCC, 1998]
- There is widespread evidence that glaciers are retreating in many mountain areas of the world. For example, since 1850 the glaciers of the European Alps have lost about 30 to 40% of their surface area and about half of their volume [Haeberli and Beniston, 1998]