Lifeblood of London
London is defined by its relationship to the physical landscape although it can sometimes be hard to see the wood for the trees in this urban jungle. Tower Bridge, the Houses of Parliament, the skyscrapers of Canary Wharf – none of these would form an iconic backdrop to the city without the mighty Thames flowing timelessly by. And so it was entirely fitting that Dr. Becky Briant, Programme Director for the MSc degree course in Climate Change Management at Birkbeck, decided to devote an entire lecture on the challenges to the future of the river and her citizens under climate change.
Effects of climate change on the river
“We are living in what some analysts describe as a carbon military industrial complex”, she says rather ominously. Dr. Briant makes liberal use of graphs to support her case including various emissions scenarios that model the predicted outcome in terms of changes to weather patterns. “The evidence is pretty strong that we are causing the changes we’re seeing”. We’re currently on track for a 4°C rise in global temperatures by the end of the century. “There’s a certain amount of climate change that’s going to happen no matter what we do”, Dr. Briant adds.
So what lies in store for us? We can expect wetter winters where peak flow in the river could increase by 40% by 2080. Between 3-24 billion litres of freshwater already flows over Teddington Weir, the upper limit of the tidal Thames. London is particularly vulnerable to flooding due to impermeable surfaces, whether that be concrete or the clay-rich impermeable soil beneath our feet. We can also expect drier summers and more intense rainfall events, which will in turn affect water quality in the river. And then there is the whole issue of surface water on our many paved streets that the Drain London Forum is seeking to address in a sustainable way.
So what does the future hold in store for the Thames?
London is fortunate to have a vital piece of infrastructure in place that can protect the city from tidal flooding, the Thames Barrier. The lifetime of this key flood defence is predicted to expire in the 2070’s due to sea-level rise at which point a new barrier further downstream at Long Reach (or Tilbury) has been proposed. But already the barrier is having to be closed more frequently due to tidal surges. Lest we forget, 307 people died in the UK due to the floods in 1953, which prompted the construction of the barrier in the first place.
Professor Gerald Roberts, Head of the Department of Earth and Planetary Sciences, remarked at the lecture’s end that he was “particularly struck by the image of London with so many rivers running through it”. So next time, you’re out and about, keep an eye open for all those small creeks, tributaries and hidden rivers that feed the mighty Thames and remember that they could yet rise up in response to climate change. And so hopefully will we, the citizens of this great city, to take action before the cost is too great.
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