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Hothouse Earth by Bill McGuire – Review

Hothouse Earth by Bill McGuire - Review
Photo by Stanley Li on Unsplash

Hothouse Earth: An Inhabitant’s Guide by Bill McGuire, was published as climate breakdown became impossible to ignore. The book arrived during the summer that the UK experienced its hottest day on record. Europe, the US and the Middle East have roasted in relentless heatwaves. Drought and wildfires reigned supreme, and this is just a taste of the future.

None of these events will come as a surprise to readers of Hothouse Earth, which spells out clearly how bad things will get. In summary, everyone and everything is at risk from climate breakdown. Not even the tech billionaires will be spared, according to McGuire.

Hothouse Earth is a concise and easily-digestible guide to climate change, covering everything from how and when the science developed, to what the future will be like. This book should be mandatory reading for everyone who has a stake in the future.

The book begins with COP26, the November 2021 climate summit in Glasgow, which the world hoped would lead to a major concerted push to tackle the climate crisis. McGuire writes that to have a chance of keeping the global average rise in temperatures to 1.5C, “We need to see emissions down 45 per cent by 2030… Instead, we are on course for close to a 14 per cent rise by this date that will almost certainly see us shatter the 1.5°C guardrail in less than a decade.”

We’re currently on a path towards 2.7C (by 2100) according to Climate Action Tracker. Even if the goals agreed in Glasgow were met, the rise in temperatures would still be over 2C. This kind of temperature increase, “Will seriously threaten the stability of global society.” However, the book points out that every tenth of a degree of extra warming will bring added disaster, so we must fight to urgently bring down carbon emissions.  

Dancing With Danger

According to Hothouse Earth, humanity has added 2.4 trillion tonnes of CO2 into the atmosphere. This is a sobering figure. McGuire says that the last time CO2 levels were as high as now was during the Middle Miocene Climate Optimum (MMCO), around 15 million years ago. During this time, temperatures were 2-4C higher than now, and sea level was 20m higher than today. A warning perhaps of what’s to come?

But in terms of the speed at which we’re releasing CO2 into the atmosphere, the last time anything comparable happened was 56 million years ago during the PETM, which saw global temperatures rocket by a world-transforming 6-8C. So pronounced were the changes, that palm trees could be found in Siberia, along with crocodiles in the Arctic Circle. The concerning thing is that the speed of CO2 release in the PETM could have been as little as a billion tonnes per year. Right now, “Human activities are pumping out the gas at a rate around 40 times faster,” writes McGuire. This doesn’t bode well at all, and as Hothouse Earth says, it’s possible that CO2 has never been released at the rate we’re pumping it into the atmosphere. Could this mean that we’re about to experience a rate of corresponding heating that has never been seen before?

Climate Change Science

Hothouse Earth neatly tracks the developments in the field, starting with Eunice Foote in 1856, through John Tyndall in the 1860s, Svante Arrhenius, Roger Revelle in the 1950s, all the way through to Dr James Hansen’s testimony to the US Senate in 1988. This is largely regarded as the moment when the world became fully aware of the threat of climate change – 34 years ago. In those intervening 34 years, the Intergovernmental Panel on Climate Change (IPCC) was set-up.

The IPCC has produced six assessments, the last of which was regarded as the last one that will be released while humanity still has a chance to meaningfully tackle the climate crisis. How has climate change worsened between the first IPCC report and the sixth report? McGuire says that, greenhouse gas emissions have increased 43% and atmospheric CO2 has increased almost 19%. An unforgivable failure of politicians in tackling this gargantuan threat.

Climate Change Happening Now

Hothouse Earth says some researchers are worried that Greenland may be close, or have already passed a tipping point that will see its ice melt and raise sea levels by around seven metres. As ice melts, the earth rebounds from beneath the weight. This leads to increased earthquake and volcanic activity. On the other side of the world, the Pine Island Glacier in Antarctica, could approach a tipping point in the next 10 years. The Thwaites Glacier in Antarctica is also at risk of breaking up. It already contributes 4% to sea level rise.

The Amazon rainforest has also taken a massive hit. Able to absorb 500 million tonnes of CO2 per year, it is now emitting one billion tonnes of CO2 into the atmosphere annually, making it a net carbon source. One reason for this is that warmer temperatures lead to a decline in photosynthesis whereby plants absorb CO2. Meanwhile respiration increases, thereby releasing CO2 into the atmosphere.

Climate Breakdown Going Forward

The forecast for the future looks bleak. A taste of some things we might expect include:

  • Estimates vary significantly, but there could be anywhere between 250 million – 2 billion climate refugees within the next 80 years.
  • By 2070, about 20% of the land surface could be uninhabitable due to extremes of heat, weather, drought and disease.
  • Civil disorder is likely to increase, as climate refugees try to enter Northern countries. Wars and conflict over resources could ensue. According to Hothouse Earth, an estimate says that 1C of warming could lead to a 14% rise in social unrest.
  • The Atlantic Meridional Overturning Circulation (AMOC) could be on the way to shutting down. This crucial ocean conveyor, takes heat from the tropics to the poles, and shifts cooler waters back.
  • Plants on land may only be half as effective at CO2 removal within the next two or three decades.
  • Droughts could lead to a 50% decrease in agricultural yields within the next two decades.

Climate Action

McGuire praises Greta Thunberg, Fridays for Future and climate activist organisations like Extinction Rebellion for helping put the climate crisis on the agenda. According to Hothouse Earth, some things we need to achieve include:

  • Fossil fuel extraction needs to stop as soon as possible. Fossil fuel subsidies must end.
  • Banks need to stop funding fossil fuel projects.
  • Pension schemes, wealth funds etc. must divest their stock in these companies.
  • We need to undertake a massive global tree planting scheme.
  • Reduce meat consumption.

The message from Hothouse Earth is that we’re on track to surpass the crucial 1.5C and even 2C targets agreed in Paris in 2015. This means we’re heading for a hellish future. However, we can still influence how quickly things get worse and our goal now must be to act with urgency to put the brakes on rapid climate breakdown. We simply can’t bury our heads in the sand any longer, especially as the wildfires, droughts and heatwaves begin to close in on us. Find a reason to fight, whether that be for future generations, for the animals who have no voice, or just because it’s the right thing to do. And then join the climate movement and be part of history at this critical moment.

My new cli-fi children’s picture book is Nanook and the Melting Arctic. Nanook is a caring polar bear who lives in the Arctic. But when his igloo starts melting, Nanook must find a way to save his friends and his home. He knows that the people who can help are also those who’ve caused the problem and he must find a way to convince leaders to act on the climate crisis. You can purchase Nanook from Amazon’s global stores including Amazon UK and Amazon US.

Published inBook ReviewsReviewsThe Climate Crisis