Download The science behind climate change

July 2012
The science behind climate
change briefing
Introduction
Climate change is one of the most pressing issues of our time. Though it has
been a popular topic in recent years, interest in climate change has seemed
to decline as the economic downturn felt across the globe has taken
precedence. Nonetheless, action must urgently be taken, as the negative
impact felt by future generations is likely to vastly increase unless we
take action now. It is important for individuals and public & private sector
bodies to know what they can do to tackle the impact of climate change.
However, the government is ultimately responsible in tackling the
impact of climate change by taking a strategic leadership role in raising
awareness and committing adequate and sustainable resources to
reduce carbon emissions and save our scarce resources.
Also the voluntary & community sector (VCS) organisations with their
close ties to individuals and communities have a unique opportunity to
make great strides in reducing the negative impacts of climate change
when working with and supporting local communities.
For more information on climate change policies you could read LVSC’s
recent briefing on climate change policy at a national and London-wide level.
It summarises current policies and initiatives and the opportunities for the
London VCS around adapting to and mitigating against climate change.
The aim of this briefing is to provide a lay overview of the science
behind climate change and what this might mean for us now and in the
future.
The meaning of climate / climate change
First, we must define what climate means and differentiate it from weather.
While weather is the temperature, wind, precipitation, etc. that changes from
hour to hour or day to day, climate is essentially the average weather at a
given location over a given period of time. The location can be as specific as
the city of London or as broad as the entire globe, while the period of time can
range from a single month to several years. Climate change, therefore,
describes the variations in climate elements over a significantly long interval.
What is global warming?
Often, when people hear climate change they assume it means global
warming, a popular misconception. While the term climate change
encompasses global warming, it also includes things like variations in sea
level and severe/extreme weather events. Although the global average may
show a rise in temperature, the variability of individual weather events in
1
different regions means not every consecutive year will be warmer than the
last.
What is / are the greenhouse effect / greenhouse gases?
Another popular, but often misunderstood term is the greenhouse effect. This
describes how gases in the atmosphere (such as water vapour, carbon
dioxide, and methane) trap heat from the sun. These gases allow sunlight to
pass through the atmosphere but prevent the heat from escaping back into
space. Without this process, the Earth would be much colder and
uninhabitable for most kinds of life. The greenhouse effect, and its associated
gases, occur naturally and have been for millions of years. However,
emissions due to human activity are directly increasing the amount
greenhouse gases present in the atmosphere and this is believed to
contribute to climate change effects.
How is our climate changing?
While the Earth has witnessed cyclic fluctuations between warm and cool
periods throughout history, changes in the climate over the last century have
been rapid. Since the last ice age, the Earth’s average global temperature has
hovered around 14°C. During the last hundred years though, that
temperature has risen about three quarters of a degree. While this may
sound like a very small change, it has great implications. This has caused
changes in rainfall patterns, sea level rises, and the melting of ice sheets,
glaciers, and sea ice around the world.
For more information on climate, climate change, and the environmental
impacts, visit the Met Office and DECC websites.
What does this mean for us?
According to the Intergovernmental Panel on Climate Change (IPCC), a
number of important impacts on human activity are possible. First and
foremost are continued temperature and sea level rises. Left unmitigated,
greenhouse gas emissions could increase the global temperature by a further
1-6°C over the next century. The continued increase in temperature could
lead to more severe heat waves and droughts in some areas as well as
increased heavy precipitation in flooding in others. Further sea level rises
could threaten low-lying coastal areas and small island states. These changes
have huge implications regarding agriculture, human health, plant and animal
life, and economic effects.
What are the implications for London?
Climate change (particularly rising temperature and sea level) in the UK could
lead to:
 Increased electricity demand for cooling in summer and the rising
costs of energy bills
 Decreased electricity demand for heating in winter
 Greater risk of drought/flood, depending on the area
 Increased water supply shortages due to periods of droughts
2



Decreased crop yields elsewhere, which may affect the food supply in
the UK
Reduced air quality (see LVSC’s air quality briefing)
Reduced comfort in buildings and public transportation due to over
heating
For more information on the social and economic impacts of climate
change and what action VCS can take, visit the NVCO website.
Conclusion
Climate change is occurring and it is widely accepted in the scientific
community that human interaction with the environment is contributing to this
rapid change. It will almost certainly have profound impacts on both society
and daily life globally and within London in the near future. Climate change is
an extremely important matter and should be of particular interest to the
VCS, whose connection with London communities allows them to be a
driving force in changing environmental behaviours.
This briefing was produced by Adrian Hornung (BSc Meteorology),
LVSC Intern
July 2012
Climate Change Leaders for Low Carbon London project is funded by
City Bridge Trust. The project is supported by a number of partners.
3