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Keep cool

The shocking pictures on our TV news of wildfires sweeping through communities in the south of England, reducing homes to a charred shell and destroying any vegetation in its path have starkly illustrated the need for the UK to wake up to climate change – and keep cool.

Yes, we have had hot summers in the UK since we started keeping daily records 250 years ago, but never have the temperatures reached 40C and never have the climatic conditions been so perfectly aligned to fan the flames.

If net zero is the target we need to reach to end our dependence on fossil fuels and so prevent further global warming, then a complete overhaul of infrastructure in the UK is needed to ensure we can live as a safely as possible with the new norm of temperature extremes.

It’s perhaps understandable that in a country more famed for its cold winters than hot summers that the debate on sustainable living has tended to focus on how we heat our homes. Now as we become aware of how high temperatures prevent our ability to work, travel and enjoy downtime and even to threaten life, the need to be able to reduce temperatures in buildings is plain for all to see.

Opening a window might have reduced temperatures in the past, but simple science tells us the opposite is true if the temperature outside is hotter than indoors.

Replacing gas, oil and coal heating systems with ground source heat pumps is recognised as vital if we are to reach net zero by 2050 – the good news is such systems can be used to cool homes as well as heat them.

In the UK the difference between the highest and lowest surface temperature ever recorded is a staggering 66 °C – the recent 40°C in Lincolnshire and the -26 °C recorded in Shropshire in December 1982.

The prevailing weather impacts less and less on temperature the deeper underground you go and hardly at all after 10-20m when the heat from the earth’s core and the insulation of the soil above take over.

Ground source heating systems can utilise this natural phenomenon. When it’s cold we can extract heat from the ground into our homes, when it’s too hot we can remove heat from our homes into the ground – not a fossil fuel in sight.

The biggest determinant of how rapidly people convert to ground source from fossil fuels will be affordability. Currently the UK Government offers a grant of up to £6,000 towards the cost of homeowners making the switch. It’s a start but just half the amount being offered in other countries.

To learn more about the benefits of ground source heat pumps and how they work, take a look at this video produced by The New York State Energy Research and Development Authority.