Portsmouth Climate Action Network

Added to which we get years like 2007 when the rain stayed away in April and turned up in July. This makes this “global warming” thing very confusing.

How warm is it getting?

Global average temperatures have already risen by 0.8°C since the late 1800’s. That may not sound much but remember that we are talking “average” and that average is currently about 14.5°C. So in relative terms 0.8 equates to more than 5%.

Of more relevance is the fact that two thirds of this 0.8°C rise has been in the last 30 years i.e. the rise is not linear but worryingly exponential. Eleven out of the last 12 years have been the hottest on record and the 1990’s were, globally, the warmest decade in the last 100 years. Exponentially…imagine a credit card debt that has no interest paid off…rising steeper and steeper.

The resultant hotter air that is all around us is holding more water and becoming more humid – leading for example to the incidence of more violent hurricanes (although there’s lots of debate on this one). The oceans are soaking up about 80% of the heat in the air making them expand and sea levels to rise (in addition to the rise caused by melting ice). Presently the oceans are rising at over 3mm per annum on average. That’s about the thickness of a £1 coin.

Average temperatures are projected to rise further by 1.8 - 4 degrees by the end of the century. The last time global warming happened at this pace was about 125,000 years ago and it resulted in a sea level rise of between 4 and 6 metres (all that melting ice and expanding water). So for us in Portsmouth that is of particular relevance…

Who is telling us all this?

As far back as 1988 the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) established the Intergovernmental Panel on Climate Change (IPCC) in recognition of the problem of potential global climate change.
To quote the IPCC:

“The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation. The IPCC does not carry out research nor does it monitor climate related data or other relevant parameters. It bases its assessment mainly on peer reviewed and published scientific/technical literature.”

An update on the IPCC’s latest assessment was published in February 2007. The previous report was in 2001 and the latest data unfortunately paints a more pessimistic view. Despite this many scientific observers felt that it still erred on the side of optimism. The full IPCC report will be published/adopted in October 2007 and we will tell you some more then.

In the UK there is a more specific government funded study that draws on the IPCC report and looks at likely effects on the UK in isolation. This is called the UK Climate Impacts Programme (UKCIP). It is funded by DEFRA and based at the University of Oxford. UKCIP is part of a wider programme of research into climate change being undertaken by DEFRA.

UKCIP currently publishes very generalised climate impacts data that is based on a 2002 model. However “UKCIP08” which is underway will give more detailed climate impacts based on more detailed modelling and taking account of the latest IPCC data. So yes it will most likely be more revealing…

You can see more on UKCIP at:  http://www.ukcip.org.uk/default.asp

You can see more on UKCIP08 at: http://www.ukcip.org.uk/scenarios/ukcip08/what_is_ukcip08.asp

More locally the South East Climate Change Partnership (SECCP) seeks to investigate, inform and advise on the threats and opportunities arising from the impacts of climate change in South East England and to promote adaptive planning in the region. SECCP serves as a link to UKCIP.

You can see more on SECCP at: http://www.climatesoutheast.org.uk/about.php?back=index.php

What are the likely impacts?

Global

• Overall increase in temperatures by 2 degrees C cause melting of ice caps and glaciers
• Sea levels warm and subsequently rise by 1 metre (by 2100)
• Mass migration of wildlife that prefer alpine conditions to the poles – mass extinction
• Mass migration following starvation and drought – deserts spread across southern Europe following forest fires

National - UK

• South East experience hottest temperatures on record made worse by heat islands in cities
• Portsmouth,Cardiff and Hull rely on their sea defences more and more
• Loss of threatened species – sea birds particularly vulnerable
• Insurance crisis due to flood losses drives up house insurance premiums and affects mortgage lending criteria
• Deaths of elderly people during heatwaves

Local - Portsmouth

• Heat island affect in densely populated areas
• Repeated flooding from rising sea levels and flash storms
• Alien wildlife species invade and overwhelm natural population – loss of local biodiversity
• No-go areas for insurance companies and problems with obtaining mortgages

What can be done?

The key is slowing down the thickening of that atmospheric duvet we’ve been talking about. CO2 has an effective lifetime in the atmosphere of about 100yrs so with rapidly increasing CO2 emissions the duvet is getting thicker on balance and thus temperatures are rising.

Due to the greenhouse gases that we have already emitted scientists estimate that we are already committed to global temperature rises of 1.2-1.3°C. This is because there is a natural lag (or inertia) in the climate system. Thus even if we ceased all CO2 emissions tomorrow (and we can’t anyway) we cannot avoid some harmful effects.

Scientists believe that the life will be bearable in the UK if we can keep the average global temperature increase under 2°C above pre-industrial levels (remember we are already at 0.8°C) and that this equates to a maximum atmospheric carbon concentration of around 400/450 parts per million by volume (400/450ppmvCO2).

But here’s the difficult part …to stay within this limit, global greenhouse gas emissions must peak by 2015 and then be falling irreversibly. To eventually stabilise CO2 concentrations global emissions would have to fall by around 80% relative to today. Therefore the choices made now and in the next five to ten years, by politicians, decision makers and consumers (that’s all of us!) will determine the extent of the climate change effects felt by future generations (that’s our children and grandchildren).

This is why attitude and behaviour change are so important now and why PCAN also support the replacement on expiry of the international Kyoto Treaty on climate change and the introduction of a strong Climate Change Bill in the UK. We cannot merely rely on attitude change when we are dealing with something that will affect us all irrespective of race, beliefs or material wealth.

Want to know more about impending legislation? Take a look at our “What’s being done” and “The Climate Change Bill” pages.

Convinced enough to do something? Well take a look at our “what can I do?” page for some suggestions.

Definitely not convinced?

Write to us and tell us why at or come to one of our meetings and discuss it some more.