Climate crisis: should the North West expect more flooding like Storm Christoph?

Climate change is already having visible effects across the world. The Earth is warming, rainfall patterns are changing, and sea levels are rising.

These changes can increase the risk of heatwaves, floods, droughts, and fires - even in the UK, and even in the North West.

Last year, 2020, was the sixth wettest year on record in a series going back to 1862.

Was this January really that wet?

The wettest areas this January for the whole of the UK (by amounts of rain) were in North Wales and North West England, with in excess of 200mm in some locations.

A significant proportion of this rainfall was associated with Storm Christoph, which was a series of low pressure systems that brought several periods of rain across the region between 18 and 20 January.

Myerscough in Lancashire had its wettest January ever (49 year history) and Preston, Lancashire also broke its location record - the wettest January in 67 years.

Both locations recorded more than 200% of the average January rainfall.

January 2021 rainfall compared to long term average. Credit: Met Office

Why could climate change lead to increased risk of flooding?The short answer is 'a warmer world means a wetter world'. A warmer and wetter weather scenario means increased humidity - so 'extreme weather' events are more likely, even in our summer months.

Extreme weather is one of the most damaging and costly impacts from climate change and we are starting to see this at a local level here in the North West.

  • Frequency of rainfall - increasing

  • Severity of rainfall - increasing

  • No of consecutive days of rain in any event - increasing

During Storm Christoph, Preston had more than a months'-worth of rainfall in just 48 hours.

An average of 10mm of extra rainfall fell on 'extremely wet days' between 2008 and 2017 compared to 1961 and 1990. Credit: Met Office

What can we expect in years to come?

Flooding events are difficult to understand, as they depend not only on the amount of rainfall and intensity of rainfall - but local topography and geology as well.

One single wet weather event, taken in isolation, is a wet weather event. But when we look at the frequency and intensity of these events on a regional, national and global scale it then becomes an issue about climate - and a change in climate.

The likelihood of years as wet as 2020 is increasing, and is expected to continue to do so through the 21st Century.

Met Office projections reveal that rainfall extremes and higher temperatures - that we have already experienced in the UK in recent years - are expected to continue and we should expect records to keep being broken.

This places an increasing challenge on health, infrastructure and services in the UK and the North West.

Heavy rainfall overland has increased since 1950. Credit: Met Office IPCC