Oh boy, it’s hot! I have a thermometer beside me reading 27.8°C, and it’s been on the rise all day. I’m sure you don’t need me to tell you that we’ve had peculiar weather this year: a mild but soggy winter, and a lousy summer until now. Unpredictable seasons are becoming more common in this country due to global warming, but this year the planet has had another force of nature at work: El Niño.
El Niño is a climate event that starts in the Pacific Ocean. Wind and sea temperatures fluctuate from warm to cool and back again. El Niño is the period when temperatures are highest, occurring irregularly every 2–7 years. The current El Niño started last May and has now started to wane, but it has affected weather patterns all over the world.
During El Niño, a band of warm water accumulates in central and eastern parts of the Pacific, particularly off the coast of South America. Accompanying changes in air pressure disturb rainfall patterns and temperatures in many countries bordering the Pacific.
How do climate patterns all the way out there affect us?
You’d be forgiven for thinking that the Pacific Ocean is an awfully long way from the UK and that El Niño couldn’t possibly affect us here. But it does! The effects are subtle and difficult to analyse, but climate records show that El Niño in the Pacific correlates with warmer temperatures in the North Atlantic. This affects the position of the Jetstream: a ribbon of fast-moving wind, circling the planet about 11 miles above our heads. The Jetstream is largely responsible for our mild and gloomy weather.
Changes in the position of the Jetstream mean changes in wind, rainfall and temperature, although the exact changes are difficult to predict. Often El Niño years bring rain to southern Europe and colder, drier conditions to us. Equally, it can cause unpredictable, unseasonal or changeable weather.
Last winter was one of the warmest and wettest on record. Spring brought flash flooding and high winds, and this summer so far is turning out to be a hot one. Who knows what the rest of the year will hold! We can’t blame El Niño for all this – climate change is the main culprit – but it is a contributing factor.
So what does this all mean for my garden?
The warmer winter has bolstered the slug population, as I’ve moaned about in my last few posts. It’s not all bad news: slugs and pests are food for our hedgehog and insect friends, whose populations have been in chronic decline for many years. Don’t forget to put out fresh water for your nocturnal visitors, and give them shelter from the sun on hot days. Also, your plants will need more water than you think during the summer: make sure you water them at least once a day. I like to do this in the evening when it’s a bit cooler, to allow the water to sink into the soil without evaporating first.