IN SIMPLE TERMS..
The climate of the Earth is always changing. In the past it has altered as a result of natural causes (think oceans, atmosphere, orbits and volcanoes). Nowadays the term “climate change” is generally used when referring to changes in our climate that have occurred over the last 100 years or so.
The climate changes we've seen over recent years and those that are predicted over the remainder of this century are thought to be mainly as a result of the influence of human behaviour rather than due to natural changes.
In order to curb the dangers of climate change it is first necessary to understand how we as a species accelerate this change, what effects it has on the planet, and what actions we can take to reduce the strain on Earth's resources.
The “greenhouse effect” is very important when we talk about man-made climate change. It is a natural effect. A thin layer of gases (what we term greenhouse gases) in the upper atmosphere act naturally to keep the Earth at a habitable temperature by trapping some heat (primarily from the sun) – a bit like a duvet. The thicker the layer, the warmer the duvet. The six main greenhouse gases, often termed the ‘basket of 6’, are:
• Carbon dioxide (CO2);
• Methane (CH4);
• Nitrous oxide (N2O);
• Hydrofluorocarbons (HFCs);
• Perfluorocarbons (PFCs); and
• Sulphur hexafluoride (SF6)
CO2 is one of the biggest constituents of this layer and scientists have recognised that the CO2 content thus has a big influence on the climate.
It is the extra greenhouse gases (primarily CO2) that we have released over the last 200 years and continue to release (through power stations, cars and planes for example) which are now known to pose the problem. Our activities have bulked up the duvet by approximately one third of its volume and too much heat is now trapped in the system – thus the term “global warming”.
This warming (due to past emissions) is already stressing the Earth’s climatic system creating more extreme weather, melting of the ice caps, floods and droughts. It’s a bit like leaving a winter weight duvet on the bed in summer – things are going to get pretty uncomfortable underneath…
The Earth has a number of natural carbon “sinks” and it is estimated that these have actually absorbed more than half of C02 emissions over the last 200 years. This has mainly occurred in oceans but also on land through the soil and forests.
Scientists believe, however, that excess levels of CO2 can lead to these carbon sinks becoming less effective and that planting more trees is not enough to mitigate global warming. There are other side effects too. Higher CO2 leads oceans to become more acidic – enough to bleach coral the world over.
CARBON SINK DEGREDATION
An example of negative feedback is the “Ice Albedo” Effect. Ice reflects solar radiation back into the atmosphere whereas water absorbs solar radiation and gets warmer (like the Solent in summer – not that we’ve noticed though!). So as the Earth gets warmer and more ice melts there is less ice to reflect radiation and a greater expanse of water to absorb radiation. This magnifies the global warming effect.
Negative feedback loops also exist in other parts of the ecosphere. The worlds forests act as the 'air conditioning' of the planet, soaking up excess CO2 and releasing the oxygen that we breathe. As more forests are destroyed for resources and to clear way for farmland, less carbon is absorbed and is therefore left in the atmosphere, accelerating the greenhouse effect.
The Arctic tundra is also experiencing a growing feedback loop. Large amounts of methane is stored in the tundra that up until now has remained covered in ice. As this ice melts, the ground is revealed and breaks away into the ocean. This releases huge quantities of methane, a greenhouse gas far more destructive than CO2. As more methane is released, the planet heats up more and, in turn, breaks more tundra which releases more methane.
The Earth’s natural systems don’t grow in the same way as our activities on Earth. Thus we are putting stress on these systems. One of the ways this is manifested is in man-made climate change.
Want to find out more and see some nice diagrams?
Here are some useful links:
The Met Office - http://www.metoffice.gov.uk/climate-guide
The Guardian always has lots of articles and links - http://www.theguardian.com/environment/series/the-ultimate-climate-change-faq
Try their interactive Q&A model - http://www.theguardian.com/environment/interactive/2011/aug/15/everything-know-climate-change
And read a summary of the latest report by the IPCC - http://grist.org/climate-energy/the-10-things-you-need-to-know-from-the-new-ipcc-climate-report/
THE GREENHOUSE EFFECT
CAUSES OF CLIMATE CHANGE
PCAN is determined to campaign against fracking which is a process used to extract gas and oil trapped in shale rocks deep underground. Many areas around Portsmouth are earmarked for fracking - the city depends on underground aquifers in these areas for its fresh water supplies. And Highbury College will be training fracking technicians.
We believe that it is no answer to the energy crisis, it will harm the environment and it will pose serious threats to our water supply and health. We also believe that fossil fuels need to be left in the ground. See this report from University College London (Jan 14).
We need to fight hard because planning applications have been going ahead with very little public awareness.
There's no way it can be safe
It will industrialise the countryside and destroy valued environments
The risks of water pollution are enormous. Fracking involves a toxic mix of chemicals
It will cause air pollution too. Silica is needed in the process and this is really harmful.
It will release vast amounts of methane which is a really potent greenhouse gas and neurotoxic
Fracking sites are noisy, lit 24/7 and need loads of lorries bringing materials and taking away waste (to where??)
Methane has been escaping into drinking water so that it can actually be lit!
Fracking has caused earthquakes
Fracking releases huge amounts of contaminated waste water
The investment going into fracking needs to be spent on clean technology which does not release greenhouse gases and risk further climate change
Fracking uses huge quantities of fresh water - the average fracking site uses 4.2 million gallons in each well
Earlier Government promises of cheap gas have now been contradicted by industry figures, such as Lord Browne (ex CEO of BP) who now says fracking will not reduce UK gas prices.
Find out more from the links below:
Frack Off is a national campaign. They have been organising protest like the ones at Balcombe. Check out their website here.
Fracking Unsafe is a coalition of groups like RSPB and Stop Climate chaos which are opposed to fracking. Check out their website here
Just think how many people this must represent.....
Friends of the Earth are working on fracking. See their website here.
See their fracking map to see how seriously we are at risk.
Our Green MEP in the European Parliament, Keith Taylor, is campaigning hard. Download his publications here.
And this is the EU Stop Climate Change site.