A report from Australian scientists declares significant statistical proof that global rainfall is on the increase based on a century of records. The report links global warming with this increase in precipitation and predicts that continued intensification of rainfall events will lead to more frequent flooding throughout the world.
The research, using data from 8,326 observing stations which had collected at least 30 years of record over the period from 1900 and 2009, found the intensity of rainfall was statistically associated with temperature. It showed that increases of between 5.9% and 7.7% in rainfall occurred for each degree of temperature rise.
According to NASA the average temperature has increased by 0.8°C since 1880, with over two-thirds of that rise occurring since 1975. If this trend continues we will see a rise of around 0.15°C per decade.
A BBC report in January stated days of particular heavy rainfall in the UK have become more common since 1960, mirroring the increases seen in other parts of the world. It will be no surprise to hear that last year extreme downpours in the UK occurred on average once every 70 compared with the normally expected once every 100 days. If global temperatures continue to rise, however, our air will hold increasing amounts of moisture which statistically means yet more rain and, if we do nothing, the misery of the floods that go with it.
This information only serves to strengthen our viewpoint that the need for sustainable drainage systems (SuDS) is increasingly important. To help in managing more intense rainfall, their implementation must be seriously considered by all local and national governments worldwide. If predictions about our climate are right, then we should maintain the drive for sustainable drainage to help manage the increased rainfall in our built environment. The need to engineer long term solutions that protect environments against the now all too common floods is recognised in the Floods and Water Management Act and we should welcome the careful consideration and subsequent implementation of SuDS in 2014 in England.