Climate Change and the Summer 2007 Floods in the UK

By Lane, Stuart N. | Geography, Summer 2008 | Go to article overview

Climate Change and the Summer 2007 Floods in the UK


Lane, Stuart N., Geography


Introduction

We have always bemoaned the wetness of the 'Great British Summer'. The summer of 2007 was, without a doubt, one of the wettest on record, but we have had wet summers before, indeed some quite recently. Analysis of the Meteorological Office's rainfall series for 1914-2007 for the United Kingdom (Figure 1) shows that in about 20% of years the UK's summer rainfall was greater than the median winter and autumn rainfalls. However, the UK's summer rainfall for 2007 (357.1mm) was the second highest on record, and only marginally less than in the wettest year (1956, 358.4mm). But one thing stands out in relation to 2007: the way in which, in many different areas of life, the summer of 2007 has become linked to the belief that our climate is changing. Consider, for instance, Prime Minister's Question Time on 25 July 2007, immediately in the aftermath of the flooding in Central England (Hansard, Volume 463, Part 130, Column 834):

Sir Menzies Campbell: 'The Prime Minister was responsible for the establishment of the Stern review, which he will recall pointed out the severe economic consequences of climate change. Is it not clear from the events of the past few weeks that we cannot afford not to take the necessary steps or indeed, not to spend the necessary money, in order to mitigate the effects of climate change?'

The Prime Minister: 'The right hon. and learned Gentleman is right. The Stern report, which the Treasury commissioned, said that global warming is very likely to intensify the water cycle and increase the risk of floods. It is an accepted part of the Stern recommendations that we have to do more ...'

In this article, I think through the relationship between climate change and the UK floods of 2007 and, in so doing, show that in order to understand the range of scales of climatic variability upon which any kind of climate change signal will be superimposed, we need to take a more historical perspective which has a much stronger grounding in the atmospheric and oceanic drivers of the UK's weather and climate.

The weather 'conveyor belt'

The UK's 'weather' is driven in the main by weather systems originating in the Atlantic. A complex interaction between high and low pressure systems, and the associated 'conveyor belt' of the Circumpolar Vortex, or 'jet stream', acts to determine whether the UK is influenced by 'high pressure', or 'low pressure' systems (Figure 2). The jet stream is a current of fast moving air, thousands of kilometres long, hundreds of kilometres wide and a few kilometres deep. It is a dynamic feature, spatially and temporally, bounding polar air on the north side and cooler air on the equatorward side. There are three primary dynamical aspects:

* strength

* position

* sinuosity

The strength of the jet stream is primarily a function of the temperature gradient between the equator and the pole. This gradient is weakest in the summer, and therefore the jet stream is commonly weaker in that season. In the winter, the gradient is strongest and the jet stream is commonly stronger. Its average position migrates northwards during spring, to lie north of the UK in a typical summer. It migrates southwards during autumn to lie south of the UK in a typical winter. Its sinuosity varies from weak to strong. When the sinuosity is strong, of particular importance is the position of ridges and troughs (Figure 2a). When a trough is positioned close to the south or south-west of the UK, there is generally divergent air aloft, leading to rising air and low pressure at the surface. This draws in air which tends to rotate counter clockwise, leading to cyclonic weather systems, called extratropical cyclones in the mid-Latitudes (Figure 2b). The development of a cyclone is called cyclogenesis, and this pulls warm tropical air northwards and cool polar air southwards, with the air masses mixing along fronts. As the warm air moves northwards it encounters cooler polar air and is forced to rise, causing condensation and precipitation as it does so, along what is called a warm front. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Climate Change and the Summer 2007 Floods in the UK
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.