Curious Cook: Facing up to climate change

Curious Cook: Facing up to climate change

There is a little book on climate change that everyone should read. It is only 60-odd pages, written by a young Swedish lady called Greta Thunberg and in it, she questions why our societies are ignoring the warnings from a growing majority of scientists.

There are many scientific warnings about how we humans as a species are indiscriminately destroying our own natural environments. This has caused the extinction rate of life to be around 5,000 times the natural rate of extinction – the natural rate of extinction if human activities are absent would be less than one per year, so humans are probably causing the extinction of some 2,000 species a year, perhaps more.

As mentioned in earlier articles, losing biodiversity is not a good way for us to survive long-term as we need biodiversity to preserve our natural sources of food and medicinal supplies.

By clearing forests, polluting the environment and applying chemicals wholesale on forests, vegetation and wildlife, humans may have already destroyed the unknown species of bacteria, fungi or plants that can stop future plagues, diseases and famines.

But Thunberg’s warning is only about a single subject: climate warming. She is genuinely concerned about her future, and as a teenager, her concerns are the same as for your children or your children’s children. And she rightly points out that it is all our responsibility to do something about this problem now before it is too late.

Inaction and denial

Although few people would deny that a plastic continent over 135 million hectares floating in the Pacific Ocean is extremely undesirable, this fact still does not deter many millions of people from using plastic bags and synthetic coverings. In fact, if one goes into any modern supermarket these days, in many cases over 80% of the produce sold are presented, gathered or sealed in plastic wrappings.

The teen activist’s campaign against climate change has resonated with youths worldwide.

The schemes offered for “recycling” such plastics are seldom more than fake news – the reality is that much of these “recycled” plastics are exported from Europe to Asian countries such as India and Malaysia where these waste plastics are simply burnt, causing serious toxic air pollution in parts of those countries.

Similarly, there are a lot of deniers about climate change, including United States President Donald Trump and various other governments and business groups. Their arguments are usually based on the fact that Earth has been warmer in the past and therefore the current warming cycle is claimed to be part of a natural sequence of events which has nothing to do with human activities.

On the surface, this appears to be plausible, so let us explore it in more detail. The main detectable link between past planetary warming events and the current episode of global warming appears to be the amount of carbon dioxide (CO2) in the atmosphere, which is currently over 413 parts per million.

In the past, the planet had even higher levels of CO2 in the atmosphere; for example, there were 4,000 parts per million of CO2 around the end of the Cambrian Period (before the Ordovician Period) half a billion years ago, down to as little as 180 parts per million during the Quarternary Period around two million years ago. Some papers suggest that Earth may not have had levels of 400 parts per million of CO2 in its atmosphere for 20 million years.

So it is undoubtedly true that CO2 levels had been higher before in geological history, at least during the Cambrian period, so the next question is: what were the conditions on Earth then?

From available data, it would appear that the global temperature was on average 14°C higher than today, and sea levels were around 120m higher as well. And apart from possibly some moss, no forms of land-based life existed then. Interestingly, before the Cambrian period, during the Neoproterozoic Era (between one billion to 541 million years ago), the planet was 2°C cooler than today, so the average increase of 14°C (compared to today) during the Cambrian period was a very significant event.

Since then, higher levels of CO2 have been consistently associated with periods of global warming, and in the past, such high amounts of CO2 were usually caused by natural events such as geological activities.

So we appear to have a geological correlation between high levels of CO2 and higher global temperatures, but climate deniers still insist that CO2 may not be the single agent that caused global warming. They point out that CO2 levels may just be a symptom (or coincidence) of global warming, and in any case, the current levels of around 413 parts per million are smaller than levels in the past.

Again, that sounds plausible at face value. They, however, forget to mention that humans have also destroyed huge parts of our planet’s ozone layer allowing more solar radiation to hit the planet. In addition to CO2, we are also adding other greenhouse gases into the atmosphere such as methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride, as mentioned in the Kyoto Protocol.

Heavy flooding is one of the consequences of global warming. Photo: AFP

If it was just CO2, deniers may have a small point but in the overall picture, the arguments for suggesting that climate change has nothing to do with human activity do not carry any sensible weight.

We also do not have geological data for the other gases because they were not retained in the fossil samples or they did not exist in the past as they are only produced as a result of human industrial/farming activities.

So it might be suggested that concentrations of atmospheric CO2 should be treated more like a predictive gauge for current and future global warming events.

What lies ahead

And the next question would probably be: what happens next? The best way to investigate this is to look at what is happening now when the sensitivity is most accurate. By this I mean, as an example of sensitivity: if we want to measure rainfall, we measure it when it rains, not estimate it from the height of grass.

Current global temperatures are already up around 1°C since 1951. Seventeen of the warmest years in human history have occurred since the 21st century, and it looks like 2019 will become yet another warmest year. The graph is simple and worrying as it is an accelerating line heading upwards.

Therefore, the prognosis suggests strongly the future will be more of the same.

The pond of the Landes in Lussat is turning into a stretch of fine sand, as the natural protected area experiences one of the worst droughts the Creuse region in France has ever seen. Photo: AFP

The other worrying issue is something seldom mentioned: there are no known natural factors which can reverse this trend towards global warming.
Apart from possibly a large volcanic eruption spewing enough dust to cover the planet (and this will cause a series of even more severe problems to humans), nothing in nature is likely to reduce the established trend towards a warmer planet. And this trend is leading to massive problems for future human generations.

Some 70% of the 7.6 billion humans alive today live around coastal areas and cities which will be affected by sea level rises. And much of the rest of the population are living in areas experiencing water/weather stress conditions such as droughts, severe storms or hurricanes. So Thunberg has a point, in that the only factor that can seem to reverse such a disastrous future for humanity appears to be humanity itself.

We can all do our little bit, in simple ways. For example, a kilogramme of beef can add up to 1,000kg of greenhouse gases (GHG) into the air. But each kilogramme of poultry will add less than four kilogrammes of GHG.

If we care enough, we can all figure ways to reduce our GHG contributions, and importantly, we can also make our governments and societies know that we care enough about future generations of humans to give them a chance of living in a proper planet instead of one severely blighted by our careless disregard for nature. As mentioned, read Thunberg’s little book. It costs less than the price of a coffee. What have you to be afraid of?

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