Hothouse Earth event in Cambridge hears warning that 1.5° milestone could happen this year, with ‘catastrophic’ consequences

The Earth is set up for a cascade of environmental catastrophes with accompanying societal breakdowns - and the only question left is how soon the unfolding disasters will engulf humanity, warned author Bill McGuire at St Philip’s Church on Thursday evening.

Prof McGuire’s no-holds-barred talk at the Mill Road church, titled ‘Hothouse Earth: An Inhabitant’s Guide’ after his recently-published book (Icon Books, £9.99), was followed by a Q&A in which the audience voiced their frustration with the burdens the pace of development places on the region’s ecosystem, particularly the unique chalk streams around Cambridge.

Sue Buckingham, of hosts Friends of the River Cam, introduced the guest, saying: “This is the first in-person talk from Friends of the River Cam and it’s great to see everyone here.”

She added: “This area has 85 per cent of the world’s chalk streams, it is the Amazon of the world’s chalk stream ecosystem – but our local rivers are being destroyed by over-abstraction. Bill’s book illustrated how quickly and how forcefully environmental degradation is taking place.”

Prof McGuire said the book was written for “our children and our grandchildren who will be living in a world completely unrecognisable to our grandparents”.

The chances of avoiding the catastrophic consequences of a 1.5 degree increase in global temperatures are now negligible, he said.

“Emissions would need to fall by half of what they are today in the next 18 months to avoid a 1.5 rise,” he said. “In theory it’s possible but it’s like being tied to a railway track and there’s a train thundering towards you. You could escape in time, but you almost certainly won’t.”

This “thundering train” has already arrived for many.

“If you are one of the 33 million people in Pakistan affected by flooding, or living in California where wildfires are causing so much devastation, you’d say climate change is already here. Avoiding 1.5 is practically impossible, even 2 degrees is going to be difficult. Atmospheric carbon dioxide (CO2) pollution was 280 parts per million (ppm) before the industrial revolution, and we’re now at 420ppm. Modelling is one way we can see where we might be headed.

Prof McGuire, who had come down from the Peak District where he lives, then showed the audience a series of deeply troubling graphs. Where we are today is “entirely unprecedented in the history of the Earth”, he said.

Glacial melt is setting us up for a watery future.

“Greenland is melting at a colossal rate,” he said. “The poles are heating up four to five times more quickly than the global average. Greenland is losing 400bn tonnes of ice a year – seven times the rate in the 1990s. We have reached the point where Greenland will melt entirely. If the Antarctic melts, Cambridge would be under the sea. By the end of the century we could see sea level rises of two metres or more.”

The Atlantic Meridional Overturning Circulation (AMOC) system – a large system of ocean currents that carry warm water from the tropics northwards into the North Atlantic – is also under threat, and could actually result in the European “bubble” caught in a massive temperature fall of 3 degrees.

In addition, methane – “86 times worse than CO2” – could be unleashed.

“There’s 1.4 trillion tonnes of methane locked into land in the Arctic,” Prof McGuire said. The Earth’s crust could be affected if the melting continues, triggering massive landslides.

“These are the physical processes, but these changes cause famine, civil strife, wars, a huge mental health toll, and loss of air quality. As temperatures rise, the human body can’t handle it.”

Food will become a huge issue.

“The human population will need 50 per cent more food by 2050, but crop yields will be down 30 per cent. This is only 27 years away. Climate breakdown and war go hand in hand.”

Accelerating climate breakdown is likely to affect South-East Asia the most.

“All the countries in South-East Asia will be fighting for water and power. Pakistan, India and China are nuclear powers, which is very worrying.”

The cascades are imminent.

“It’s perfectly possible we could reach the 1.5 degree milestone later this year or next year,” the broadcaster noted.

On the day the UK government announced its updated environmental policy, which placed huge emphasis on largely unproven carbon capture techniques and the go-ahead for further oil and gas exploration, Prof McGuire warned: “If fossil fuel companies are allowed to extract all the oil from the Earth it would add 3.5 trillion tonnes of CO2 into the atmosphere.”

In the Q&A, a member of the audience expressed horror at the forecast and asked what can be done.

“I can’t see governments getting on top of this,” Prof McGuire replied. “Organisations like Extinction Rebellion and Just Stop Oil have done a great job in getting climate change to the top of the agenda. One of the new initiatives pairs climate scientists with comedians. “

(Climate Science Breakthrough uses comedians to ‘translate’ jargon into ‘human’.)

What would you do if you were Prime Minister Rishi Sunak for a day, asked activist Pushpanath Krishnamurthy.

“I would stop all subsidies to all fossil fuel companies, increase the costs to their insurers, and put a tax on wellheads, but there’s no political will to do that,” Prof McGuire replied.

Tony Booth, of Friends of the River Cam, urged citizens to “be less polite”.

“We live in a city where rapacious development is taking place,” Prof Booth said. “Anglian Water doesn’t give a damn about us. Cambridge Water is owned by hedge funds. Let’s stop being polite.”

Sue Buckingham concluded: “I’m not easily upset but it can be really affecting to hear about the impacts of climate change. We need to support each other and to hold each other and think through this because it can be really dark. Doing things together, we can be so much stronger.”