Climate Change: It is real but are we misreading or over-reacting to the impact on natural evolution of human settlement as the cause of the problem?

There is no denying that the climate is changing, and indeed we might suggest constantly changing. This has been occurring for thousands if not millions of years, with recurring droughts, floods, tornadoes, earthquakes, heatwaves, and fires. This is nothing new and occurs both incrementally and seismically. For example, about 400,000 years ago, large parts of Greenland were ice-free with scrubby tundra basking in the Sun's rays on the island's northwest highlands. Evidence suggests that a forest of spruce trees, buzzing with insects, covered the southern part of Greenland. Christ et al. (2023) pins the time of Greenland's last melting to some 400,000 years ago. In 2016, a study of a unique bedrock core drilled from under the centre of the Greenland ice sheet suggested that most, or all, of the ice covering Greenland had melted away at least once during the last 1.1 million years. This resulted in elevating sea levels and fertile land. A comparable example closer to home is the loss of the land bridges to Tasmania and New Guinea when sea levels rose ~12,000 years ago. This occurred during the climate warming process that ended the ice age that lasted from 30,000BC to 10,000BC[1].

What is new, at least over the last 200 years, is that these events are today occurring and being recorded in areas which we call human settlements, which in the distant past (and often less distant past) were affected by significant climate change events such as floods, fire and hurricanes, but not impacting humans to the same extent witnessed today because there were no (or very few) humans living in many of the affected areas (be they a floodplain, bushland, desert etc.) in most nations. What we now see is the exponential growth of human beings (i.e., population explosion) who, throughout the world, are ever increasingly settling on land that is often marginal, if not totally unsuitable, for human habitation, as well as agglomerating in cities and megacities. In many countries, the infrastructure is not built to safe standards, and there is significant overcrowding and local poverty. This is a big part of the observed “climate” problem. Whether the land is suitable or not, it is relevant to acknowledge the poor stewardship of resources by humans - over farming, overfishing etc. The consequence is that the land is poorly managed with significant negative impacts when nature decides to erupt for whatever reason. 

A question of importance, and much current debate, is what role human beings have played in creating these climate catastrophes? They might be catastrophic for humans as seen as climate warming, frequent severe weather events, and the impact on communities of these events, but possibly not so for the earth on which we live, given they have been occurring for millions of years and the earth is still here in its many revised (positive or negative) forms. The often-claimed suggestion is that humans caused all of this. One might question the extent to which this claim is valid (The science is very imprecise and subject to significant error bands). While it is true that humans have modified the sources of environmental degradation through developments designed to serve them well (so they typically believe) and have thus contributed to changes in the environmental context in which they reside and move around, it may well be that their contribution creates a correlational effect rather than a causal effect on the change in climate[2]. In other words, human interaction may indeed deliver many undesirable outcomes such as increased local air pollution and increased carbon emissions, but whether this has been enough in itself to cause (i.e., contribute significantly to) non-marginal changing climate that has been occurring well before we built our high-density cities and encouraged sprawl, and we populated almost every part of the world, and generated significant global mobility, must remain unanswered or at least questioned without full proof [3]. A priori, correlation is not the same as causality, we might all agree, but to date the dominating causal thesis is the greenhouse effect linked to human activity, and it needs more careful consideration.

Time may show that the world will survive no matter what we do to reduce emissions, and that it may be time to stop the alarmist rhetoric which does nothing to support sensible sustainability initiatives. Given an interest in transport emissions, a key contribution, which are impossible to totally eliminate, we should reflect on the importance of transport to humankind’s ability to cope with adverse weather events. How else are we going to support the communities that are affected if not by the transport of people and supplies to and from the affected areas? 

A question that will remain unanswered for now is that when we eventually get CO₂ emissions, blamed significantly on the transport sector, to a level we believe is what we need to be at, will this make any difference to the preservation of this magnificent earth or not? Some of us might question the commentary of extreme activists and the disproportionate amount of research focussed on this topic.

We reiterate how important it is to distinguish between person-made microclimatic (local) impacts, some of which can be mitigated (with sufficient political will) by better building design, behaviour change programmes etc., and global effects which might be occurring anyway. A key reason why we blame humans for enhanced climate change beyond the catastrophic forces of nature in their absence is that humans are increasingly impacted because they are ever present everywhere, and they make unwise decisions like building on flood plains. 

Acknowledgments. I thank Corinne Mulley, John Nelson and Ian Christensen for their feedback.

Christ, A.J. et al. (2023) Deglaciation of northwestern Greenland during Marine Isotope Stage 11, Science, 381, Issue 6655 pp. 330-335 DOI: 10.1126/science.ade4248.

[1] https://www.nma.gov.au/defining-moments/resources/separation-of-tasmania#:~:text=About%2030%2C000%20years%20ago%20an,Papua%20New%20Guinea%20and%20Tasmania.

[2] https://www.researchgate.net/post/Climate_Change_is_Correlation_Cause_and_Effect.

https://www.quora.com/Is-human-caused-climate-change-an-example-of-confusing-correlation-and-causation-Why-or-why-not#:~:text=How%20do%20we%20know%20global,surface%20temperature%20would%20be%20255K.

[3] This commentary does not challenge the idea that the current episode of climate warming is due to the greenhouse effect of CO2 and other gasses in the atmosphere; however, it raises the question of what this will mean for the reconstitution of the earth on which we live.