“It ain’t ‘alf ‘ot, Mum!” – We’ve known for a long time.

John writes ...

Credit: the author.

I wonder how many readers of this blog have heard of Eunice Foote, a 19th century American artist and amateur scientist. She is now credited with the first clear demonstration, in 1856, that carbon dioxide absorbs heat. She went on to speculate that if the atmosphere held more carbon dioxide, then the planet would be warmer. However, her paper received little attention and was only in 2011 that she received credit for her work. I will return to discussing that work shortly but in the meantime, I will take us back to the 1820s. Several scientists, including Joseph Fourier, wondered why, given the distance of Earth from the Sun, our planet was as warm as it is. Fourier had already developed theories and equations relating to the conductance and diffusion of heat and he considered it likely that some components of the atmosphere were trapping some of the solar radiation. In 1859, British physicist John Tyndall, carried out a series of laboratory experiments to test this idea. He found that there were indeed gases in air that acted as heat traps, the most abundant of which was water vapour, while the minor (in terms of their concentration) actors included carbon dioxide. The brilliant historian of physics, Spencer Weart, comments that Tyndall could have saved himself a lot of trouble if he had known about Foote’s work just three years earlier (The Discovery of Global Warming - A History).

Eunice Foote. Credit: Public domain.

Both Foote and Tyndall noted that, as mentioned above, the concentration of carbon dioxide in the air was low, 280 ppm in the 1850s. However, they also noted that burning coal was likely to cause small increases in the concentration but thought it would be many centuries before that had a measurable effect on atmospheric temperature. A similar view was expressed by the Swedish scientist Svante Arrhenius at the end of the 19th and in the early years of the 20th century. We need to say that this view was partly based on the rate of burning of coal prevailing at that time; many scientists believed that the relatively small increases in the release of carbon dioxide into the atmosphere could be dealt with by the ‘balance of nature’, i.e. the carbon cycle, a view which prevailed through the first three or four decades of the 20th century.

Guy Callendar. Credit: Public domain.

However, in 1938, this view was challenged by a British steam engineer, Guy Callendar. He showed that over the previous 50 years, atmospheric carbon dioxide had continued to slowly increase while the planet’s average temperature had increased slightly. Based on these findings, Callendar calculated that a doubling in the concentration of atmospheric carbon dioxide would lead to an average temperature increase of 2°C. At that time, such a large increase in carbon dioxide seemed extremely unlikely and Callendar was not alone in welcoming the prospect of a much smaller rise in temperature, possibly countering the effects of the next glaciation! And actually, Callendar’s conclusions were not widely accepted; it was another 20 years before the consensus started to shift. In 1958, an American geochemist, Charles Keeling, started to accurately measure atmospheric carbon dioxide concentrations at Mauna Loa in Hawaii. These measurements confirmed Callendar’s assertion that concentrations had increased since pre-industrial times and further that the rate of increase was accelerating. These studies were followed in the 1970s by extensive, world-wide measurements of atmospheric and ocean temperatures, showing that these were also increasing. Given that we already knew that carbon dioxide is capable of trapping solar energy (see above), by the mid-1980s it became more widely accepted that burning fossil fuels is causing climate change, leading to the United Nations establishing the Inter-governmental Panel on Climate Change (IPCC) in 1988. Since those times, between 97 and 99% of relevant scientists agree that human activity, mainly burning fossil fuels, is causing climate change. Further, the rate of use of these fuels has increased greatly during the second half of the 20th century and on into this century, thus increasing the rate of warming.

Atmospheric carbon dioxide concentrations since 1958, measured at Mauna Loa. Credit: NOAA GML.

Where are we now?
 
Readers of this blog who are UK-based will not need to be told that northern Europe has just experienced another record-breaking summer, in respect of both the frequency and intensity of heatwaves and the lack of rain. Here in SE Devon for example, in the eight weeks leading up to and including August 18, we had just 2.4mm of rain, most of which fell in a single day in late July. The effects of this drought are plain to see, as illustrated by my shot of the RSPB’s Bowling Green Marsh looking more like the Serengeti than a South Devon marsh.

Temperatures across Europe on 24 June 2026. Credit: Geo All Day.

Bowling Green Marsh, Topsham, Devon after the 2026 summer drought (top picture) and in more normal conditions (bottom picture). Credit: the author.

In relation to climate change, we agree with those who state that an individual weather event cannot necessarily be ascribed to global warming. However, the frequency with which intense weather, including storms, heatwaves and droughts, plus the slow but steady climb in the Earth’s average temperature indicate clearly that our climate is changing and that the planet is warming.

One interesting feature of the reactions to this summer is the way the print and broadcast media are reporting it. For years, the media, with just a few honourable exceptions, have been hesitant about mentioning global warming, or if they did mention it, would downplay it somewhat. The annual COP meetings are reported but then the subject fades into the background. Indeed, in a recent email to readers of The Guardian, environmental activist Tim Winton describes the media coverage of climate change as ‘…inadequate … evasive, recklessly shallow or simply dishonest.’ Even in nature programmes, the topic was often ignored, although I was pleased to note that in recent years, David Attenborough had started to warn us of the consequences of our continued use of fossil fuels. And now, to add to that, our main broadcast media have this summer, had no hesitation in talking of climate change and in suggesting that summers such as this are likely to become more frequent. And this is important: public awareness is necessary for public support of any measures both to adapt to the new normal and to reduce future warming.

What now?
 
We have very nearly reached what climate scientists have believed for many years to be a key ‘tipping point’: an increase in Earth’s average temperature of 1.5°C, compared to the pre-industrial average. Further, even if no more carbon dioxide entered the atmosphere, warming would continue for some time before reaching a new equilibrium. Climate change is real and will get worse. 

Global average temperatures since 1850. Credit: Graph from Berkeley Earth.

So what is to be done. Let me say, as I have in several talks on the subject, that it is not a matter of ‘saving the planet.’ In its long history, Earth has often been significantly hotter than it is now and will continue to survive, even if the temperature becomes too high for human flourishing. And that is the point: humankind has evolved and flourished in a relatively cool period of Earth’s history. We noted in an earlier blog post that some parts of the planet will become uninhabitable for humans by 2050 if we go on using fossil fuels at today’s rate. So there is the first action: fossil fuels must be phased out as rapidly as possible. There should be no new drilling for oil or gas nor should there be any new coal mines. I am quite alarmed that the UK Prime Minister is considering giving the go-ahead to further extraction of oil and gas from the North Sea. It may well be that we need to ‘speak truth to power’ to try to prevent this happening (although I appreciate that for friends in the USA, speaking truth to power on this topic may be very difficult).

Phasing out the use of fossil fuels is an absolute priority but how do we deal with the continued warming caused by the carbon dioxide in the atmosphere already (and with that which will be emitted before fossil fuels are finally phased out)? It is my view – and I know that some environmental campaigners disagree with this – that we need to develop carbon capture and storage techniques. Pulling CO2 from the atmosphere requires energy and it goes without saying that this energy must come from renewable sources. The feasibility of doing this is illustrated by the Mammoth carbon-capture facility near Reykjavik in Iceland but it will need to be done in suitable locations across the globe. It will also need to be carefully regulated so that the amount of CO2 captured is ‘just right’.

The Mammoth carbon-capture facility near Reykjavik. Credit: CNN

Lastly, since global warming is here to stay for at least the foreseeable future, we also need to think about coping with it. Talking about this needs a blog post of its own so I will just briefly mention one aspect, namely food production. Right across western Europe, the harvest of staple crops has been significantly reduced by the hot, dry conditions. Food shortages are widely predicted. Farmers will need to consider crop varieties that are more resilient to the changed conditions – plant geneticists have a major role to play here – and may also need to bring in crop species that, prior to global warming, could not be grown here. In that context, I recommend a paper by the UK Centre for Ecology and Hydrology (Scientists predict what will be top of the crops).

Epilogue
 
Climate change is such a large topic that in the confines of a blog post, I have only been able to scratch the surface. One topic clearly missing from the present discussion is ecology, another topic which perhaps need a post of its own. I mention it briefly here because it reminds us of the huge effects of climate change on all the living organisms on Earth – on the natural biosphere. And that leads me to think about human responsibility for the planet. I believe that God the creator has charged us with caring for the Earth, for utilising and enjoying its resources in a way that does not lead to irreparable damage and for making sure that our ‘neighbours’ – fellow humans – are OK. At present we are falling short on all counts. 

Prof. Katharine Hayhoe. Credit: Jay Godwin/ Public domain.

In thinking about this, I have been greatly helped by the writing and social media posts of Prof Katharine Hayhoe, a Canadian Christian climate scientist. On X (formerly Twitter) she describes herself as ‘Climate Scientist, Truth Teller, Christ Follower’. I especially appreciate her substack (Katharine Hayhoe | Substack) and for a particularly helpful post, may I recommend ‘Are we really doomed?’ (10 June 2025).
 
John Bryant
 
Topsham, Devon
August 2026