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Climate change report, September 2013
The latest Intergovernmental Panel on Climate
Change (IPCC) report suggests no radical
changes from previous reports (the last was
published in 2007). However, it offers more
evidence of the extent of global temperature rises,
the melting of ice sheets and sea ice, the retreat of
the glaciers, the rising and acidification of the
oceans and the changes in weather patterns. The
message is familiar and shattering: ‘It's as bad as
we thought it was.’
The report describes in impersonal terms the
collapse of the benign climate in which humans
evolved and have prospered. It refers to the term ‘climate breakdown’.
Their key findings in the report included:

Atmospheric concentrations of carbon dioxide, methane and nitrous oxide are now at levels
‘unprecedented in at least the last 800,000 years’.

Global temperatures are likely to rise by 0.3C–4.8C by the end of the century depending on how
much governments control carbon emissions.

Sea levels are expected to rise a further 26–82cm by 2100. The wide variation in part reflects
the difficulty scientists still have in predicting sea level rises.

The oceans have acidified, having absorbed about a third of the carbon dioxide emitted.

On every continent except Antarctica, man-made warming is likely to have made a substantial
contribution to the surface temperature.
The world's leading climate scientists have worked out how much more carbon dioxide humans can
pour into the atmosphere without triggering dangerous levels of climate change – and concluded
that more than half of that global allowance has been used up. The IPCC acknowledges that there
has been a ‘reduction in surface warming trend over the period 1998–2012’. This is likely to have
been caused by volcanic eruptions, fluctuations in solar radiation and natural variability in the
planetary cycle.
Within as little as 30 years the world will face nearly inevitable warming of more than 2C, resulting
in rising sea levels, heat-waves, droughts and more extreme weather.
The 2,000-plus page report was written by 209 lead authors, and found it was ‘unequivocal’ that
global warming was happening as a result of human actions, and that without ‘substantial and
sustained’ reductions in greenhouse gas emissions we will breach the critical threshold of 2C of
warming.
Natural variability and the role of the oceans in absorbing heat were cited as reasons for warming
being less pronounced in the last 15 years.
© Pearson Education Ltd 2013. Photos © Garrett Nagle. For more information about the Pearson Baccalaureate series
please visit www.pearsonbacconline.com
The most controversial finding of the report was its ‘carbon budget’. Scientists found that to hold
warming to 2C, total emissions cannot exceed 1,000 gigatons of carbon. Yet by 2011, more than
half of that total ‘allowance’ – 531 gigatons – had already been emitted.
To ensure the budget is not exceeded, governments and businesses may have to leave valuable
fossil fuel reserves unexploited. That implies if there is more in fossil fuel reserves, they should be
left in the ground.
Case study: The Maldives
It was suggested that the low-lying island nation of the Maldives would be given the date of its
extinction by the end of September 2013. Male, the Maldives capital, has a population of 110,000
and is one of the most densely populated cities in the world.
Rising temperatures will also increase coral bleaching and crumbling. Weather patterns will become
increasingly extreme and erratic. Bigger ocean swells are driving waves right over the islands,
contaminating the freshwater with salt, while thunderstorms are causing flash-flooding and
knocking out power systems. The waves are also eroding the island at rates of over 30 metres in a
decade.
Warming oceans may also be affecting the tuna industry – the Maldives' most important industry
after tourism – where catches fell by 40% from 2006 to 2011. The tuna may move to cooler water
and out of the reach of the pole and lines used in the Maldives. Alternatively, the decline may be
due to a lack of food, caused by changing weather patterns.
The paucity of long-term data makes it particularly tough to be sure about trends. Nevertheless,
there is enough now to be sure of changes, if not their exact scale. Dry seasons are extending and
intensifying, worsening the drinking water problems, which already sees drinking water being
shipped to over a quarter of the 196 inhabited islands.
There has also been an increase in dengue fever. The hotter and wetter conditions are perfect for the
mosquito. Potholes on construction sites, where mosquitoes can breed, have become a target for
government health campaigns.
One response to the threat of inundation is sand dredging from the lagoons. An entire new island,
called Hulhumale, has been created. Eventually 420 hectares will house 160,000 people, a third of
the entire population. By Maldivian standards, the new island is lofty, at 2m high.
Case study: The Somerset levels, UK
The Somerset levels may become one of the UK's climate change front-lines. Most of the land is
just a few metres above sea level. The land is marshy and has been reclaimed from the water by
man over the centuries. It remains prone to flooding.
In 2012 many parts of the area were devastated by floods that caused havoc in the spring and
autumn. The problem may get worse – by the 2080s, winters may be up to up to 30% wetter and
summers as much as 55%. Violent storms and rises in sea level could have severe impacts on the
coastal and low-lying areas of the county. Up to 6,200 square kilometres of land and some 32,500
properties are at risk of flooding.
© Pearson Education Ltd 2013. Photos © Garrett Nagle. For more information about the Pearson Baccalaureate series
please visit www.pearsonbacconline.com
The UK government suggests that the cost of damage to homes in England and Wales from river
and coastal flooding would double to over £1bn a year by the 2020s. Disruption to business
properties, power plants, roads, railways and hospitals and the growing threat of flash flooding is
likely to double this figure again.
Up to 59 million people could be affected by water shortages by 2060. Heat-waves like the 2003
event that affected Western Europe could be up to 10 times more likely by 2050. This could
increase summer heat deaths as well as buckling railways and melting roads and an increase in skin
cancer. Rises in food prices and broken supply chains would also occur.
Nevertheless, there are also opportunities. Some benefits from wetter winters and drier summers
include fewer deaths from hypothermia, improved wheat yields and more attractive weather for
tourism. On the slightly higher and less sodden ground near Glastonbury, the apples trees this autumn
are heavy with the fruit used in the Orchard Pig Craft Cider range thanks to the better summer.
Activities
1. According to the IPCC, what is the evidence for climate change?
2. By hw much are global temperatures forecast to rise by 2080?
3. By how much is sea level predictede to rise?
4. What is likely to have caused the decrease in global temperature rise between 1998 and 2012?
5. How many people were involved in the writing of the IPCC Report?
6. How much carbon can be burnt if global temperature rises are to say below 2C?
7. State the problems of global temperature increases for the Maldives?
8. What are the likely problems of global climate change for the Somerset Levels?
© Pearson Education Ltd 2013. Photos © Garrett Nagle. For more information about the Pearson Baccalaureate series
please visit www.pearsonbacconline.com
Suggested answers
1. Temperature rises, the melting of ice sheets and sea ice, the retreat of the glaciers, the rising and
acidification of the oceans and the changes in weather patterns.
2. 0.3C – 4.8C
3. 26-82cm
4. Volcanic fluctuations, fluctuations in solar radiatiom]n, and variability in planetary cycles
5. 209 authors on a 2000 page report
6. 1000 gigatons; 531 gigatons
7. Coral bleaching; rising sea levels; decreased fish catches; increase in dengue fever;
contamination of freshwater
8. Increased flooding; wetter winters; wetter summers; water shortages.
For more information visit:
IPCC
Climate change 2013, the Physical Science Basis
© Pearson Education Ltd 2013. Photos © Garrett Nagle. For more information about the Pearson Baccalaureate series
please visit www.pearsonbacconline.com