John Raine: Drive Climate Change Policy with Evidence not Alarmism

The Challenge of Opening Closed Minds

The media and many politicians worldwide continue to push a narrative of impending climate catastrophe. Whether or not you are a climate change pessimist, we live on a gradually warming planet and will need to adapt to this. Ongoing wide-ranging, balanced critical analysis is needed of the long-term history of Earth's climate, scientific models, current evidence, and underlying political and economic motivations driving the climate debate. This article addresses only limited recent evidence and analysis which indicates that climate change is real but does not pose an existential threat. 

As global temperature rise continues, alarmists will continue to ascribe much or all of this to human activity. This makes contrarian debate more challenging, but no less critical. For decades we have been subjected to a narrative of dangerous anthropogenic climate change. There are continuing calls to drastically cut carbon dioxide (CO₂) and methane (CH₄) emissions to limit global temperature rise. Yet the human-caused impact from these gases is very small. 

Prominent atmospheric physicist, Princeton University Emeritus Professor Will Happer has been in New Zealand and talking at the invitation of the Methane Accord (https://youtu.be/yxQs23Kofl4?si=NM9cY2LLazarSj97 links to his Taupo presentation). He is one of a number of respected scientists who have spoken out against apocalyptic views of climate change, and against the demonisation of CO₂ and CH₄.

Long-Term Climate Cycles and History's Lessons

Long before industrialisation, throughout geological time, Earth's climate has always cycled through periods of warmth and cold, and changing weather patterns, with CO₂ levels rising and falling in tandem with these fluctuations, and temperature rise leading the rise in CO₂. The analysis of Koutsoyiannis et al [1] also concludes that, statistically, temperature rise has led the CO₂ rise between 1959 and 2019. Moreover, these authors state that temperature-driven CO₂ outgassing from the natural environment explains 83% of the CO₂ rise since 1959. 

High CO₂ levels were not only tolerated by ecosystems historically but were also associated with periods of greater biodiversity and ecological flourishing. During the Mesozoic Era (the "Age of the Dinosaurs," from about 250 to 66 million years ago), the Earth experienced much higher levels of atmospheric CO₂, and global temperatures were significantly warmer than they are today. The Jurassic and Cretaceous periods were characterised by lush, tropical environments and diverse ecosystems. Modern climate models that predict extreme warming often fail to account for such historical precedents where CO₂ concentrations were several times higher than current levels - yet life thrived, and the planet did not experience a catastrophic climate collapse. 

During the Mediaeval Warm Period (circa 950 to 1250 AD), temperatures in some regions of the world were higher than they are today. This warm environment was characterised by increased agricultural production and economic prosperity in parts of Europe, and indeed, crop farming in Greenland. How credible then are claims that even modest further warming will lead to widespread famine and societal collapse? In this regard it should be noted that a widely cited paper in Nature by Kotz et al [2], asserting a USD38 trillion economic impact of climate change by 2049, was retracted on 3rd December 2025 after it was found to contain irremediable errors.

Initially cooler than the Mediaeval Warm Period, the 20th century warmed in its latter half – this mirrored a natural cycle that has been occurring over millennia.  Human activity has had a small effect over the past 100+ years, but natural variability has played a far more significant role in historical climate change.

CO₂ is Vital for Life on Earth

The 23^rd July 2025 USA Department of Energy (DoE) Report, “A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate” [3], authored by five eminent scientists, offers a strong counterfactual to the climate catastrophising and “the science is settled” thinking that has dominated the United Nations-led climate discussion and media. 

Anthropogenic CO₂ emissions have contributed a little to temperature rise since pre-industrial times, when CO₂ was at 0.028%. However, insisting that most or all global temperature rise is down to human activity ignores the presence of natural effects including periodic variation in planetary orbits [4], and in the sun’s radiation intensity [5]. Moreover, human activity contributes radiative forcing (warming) of just ~2.7 W/m², or less than 1%, to the total radiative energy flows in the atmosphere. 

Anthropogenic CO₂ contributes around 5% of the long-term CO₂ in the atmosphere [6, 7, 8], currently ~0.043% (430ppm). Notably, after an hour in Professor Happer’s Taupo lecture venue with a full audience, the CO₂ level was at 0.24% (almost six times that in the open air outside the venue), but the audience was comfortable and unaware of this higher CO₂ level until told.  Submarine crews routinely live with CO₂ levels of 0.2% to 0.5% (2,000 – 5,000 ppm). 

Basic radiation physics shows that a doubling of CO₂ from present levels would raise temperatures by only 0.71 ⁰C. In this regard, the analysis of Schildknecht [9] showed that, because of saturation of the absorption of infrared radiation by CO₂, a doubling of atmospheric CO₂ would lead to a temperature rise of only approximately 0.50°C. 

Similarly, Coe et al. concluded from their modelling that: “Climate sensitivity to future increases (a doubling) in CO₂concentration is calculated to be 0.50°C, including the positive feedback effects of H₂O, while climate sensitivities to methane (CH₄) and nitrous oxide (N₂O) are almost undetectable at 0.06°C and 0.08°C respectively.” Coe et al. [6] noted that water (H₂O) and CO₂ are the two main atmospheric greenhouse gases (GHG) and found that temperature sensitivity to rising CO₂ levels falls exponentially with further increases in CO₂. Lindzen and Happer [10] note in a recent paper that “achieving Net Zero CO₂ and other GHG emissions to Net Zero by 2100 would cause negligible changes in Earth's surface temperature.”

Water vapour has a far greater GHG effect than either CO₂  or CH₄, and the effect of clouds in the atmosphere on the equilibrium temperature leads to wide uncertainty bands in climate models, but the Intergovernmental Panel on Climate Change (IPCC) AR6 forecast range of a “very likely” temperature increase from a future doubling of CO₂ of 2°C to 5°C is biased high when compared with data-driven models and measured global temperature evidence. Research on the effect of clouds must continue, but neither validated analysis nor the evidence supports the massively damaging economic cost of attempts to heavily cut CO₂ and CH₄ emissions or to pursue Net Zero carbon emissions by 2050.

A core claim of those claiming there is dangerous anthropogenic climate change is that rising CO₂ levels are a threat to life on Earth. But this view ignores or denies the role that CO₂ plays in supporting life. CO₂ is an essential building block for plant life and provides the foundation of Earth's food chains.  Global warming from an improbable doubling of CO₂ would produce further greening of the planet, including increased agricultural productivity The USA DoE Report emphasises that, “Elevated concentrations of CO₂ directly enhance plant growth, globally contributing to “greening” the planet and increasing agricultural productivity.”  Higher CO₂ concentrations also improve water efficiency in crops. The reality is that CO₂ and CH₄ have been demonised.

Extreme Weather Events and Sea Level Rise 

The evidence appears weak for the claim that extreme weather events, hurricanes, droughts, floods, and wildfires, are becoming more frequent and intense due to human-induced climate change. Short-term periods of extreme weather can be too easily attributed to climate change. The IPCC itself acknowledges that the relationship between climate change and extreme weather events is complex and difficult to predict.

USA-focused analysis [3] did not show compelling evidence that extreme rainfall events are becoming more common or severe due to climate change, although, in a warming environment with greater evapo-transpiration, more heavy rainfall events might well be expected. 

Tropical cyclones expert, Dr. Chris Landsea [11], has pointed out that while there has been a slight increase in the number of reported hurricanes in the USA, this can be attributed to improved detection and reporting rather than an actual increase in hurricane activity. Furthermore, the data shows no statistically significant upward trend in the frequency or intensity of hurricanes over the past century.

One of the most frequently cited threats of climate change is rising sea levels, due to melting of polar ice caps and thermal expansion of seawater. Sea level rise is significant in some areas such as the Pacific Ocean region and projected to be problematic for some low-lying islands. Recent data from NASA and the National Oceanic and Atmospheric Administration (NOAA) in the USA [3] shows that while sea levels have risen over the past century, the rate of increase has been relatively modest - according to the 100-year tide gauge record, about 1.8 mm per year since 1993. Satellites have also measured sea level since the 1990s and give a higher figure of 3.3 mm per year. There is disagreement on the rate of future sea level rise.  The IPCC AR6 forecast is a very likely rise of 100-400 mm relative to a 1995-2014 baseline period. The higher end of this range would require a major acceleration in the rate of sea level rise. 

Big Corporations and the Push for "Climate-Friendly" Energy Solutions

A key issue in the climate change debate is the vested interest of big corporations and political elites in pushing "climate-friendly" energy solutions. Solar and wind technologies have become a cornerstone of global energy policy. Promoted as clean, cheap and sustainable, these technologies come at high overall cost and with environmental trade-offs.

Solar panels and wind turbines need vast amounts of land, and their production generates significant GHG emissions due to the mining and processing of concrete, steel and rare earth metals. Moreover, until new low-cost massive battery storage technology emerges, the intermittent nature of these energy sources necessitates the costly provision of back-up systems offering ~50% of the wind and solar installed capacity [12], often relying on natural gas or coal. This reality increases the price of power and undermines the environmental benefits solar and wind claim to offer, particularly with their relatively short 15 – 25 year operating life. 

Corporations and governments are also using the “climate crisis” as an opportunity to push "green" consumerism, where individuals are encouraged to purchase relatively costly electric vehicles, solar panels, and other "eco-friendly" products. This sales narrative is often accompanied by "greenwashing" - products marketed as environmentally friendly while ignoring the true embedded environmental costs of their production and disposal.  A stark example of this is Auckland Council’s vegetable scraps recycling scheme – a net cost both in natural resources and emissions impact [13]. 

Politicisation of Climate Change: Economic and Social Consequences

The climate change debate has become deeply politicised, with governments enacting policies that impose heavy costs on industries, consumers, and taxpayers. The European Union's Green Deal and similar initiatives in Australia and other nations have resulted in widespread economic strain, with energy prices soaring in proportion to higher percentages of installed solar and wind power, and industries facing stricter regulations. In the U.K. and Australia, for example, these crippling energy costs are causing substantial economic damage through consequent de-industrialisation. The push for Net-Zero carbon emissions by 2050 will lead to greater de-industrialisation and job losses, particularly in heavy manufacturing, but of course also in sectors such as coal mining, gas and oil extraction. 

Conclusion: A Call for Rational Discussion and Balance

Scientific debate around climate change must not be treated as settled - the paramount objective must be scientific truth. The alarmist narrative that dominates public discourse is not supported by the evidence. Long-term climate cycles, historical precedents, and the weak empirical data linking climate change to extreme weather events all suggest that the planet is not on the brink of catastrophe. Rising CO₂ levels are not a threat to life and CO₂ must be seen as a necessary component of global ecological health. Renewable energy is key part of the energy supply system but must be pursued in a way that is both economically viable and environmentally sound. Certainly, New Zealand should drop Net Zero 2050 and avoid any emissions measures that are damaging to our primary industry sector. 

Climate change has become a political and ideological battleground. A more rational and balanced debate is needed that acknowledges the complexity of the issue and the full range of scientific perspectives. The way forward requires prudence, but not rigid belief in an impending crisis.

John Raine is an Emeritus Professor of Mechanical Engineering and a former researcher in alternative and renewable energy systems. He also formerly worked in the UK engine and vehicle test plant industry.

References

1.         Demetris Koutsoyiannis, Christian Onof, Zbigniew W. Kundzewicz, Antonis Christofides, “On Hens, Eggs, Temperatures and CO₂: Causal Links in Earth’s Atmosphere”. Sci 2023, vol 5 (3), 35; 13^th September 2023,  https://doi.org/10.3390/sci5030035.

2.         Maximilian Kotz, Anders Levermann, Leonie Wenz, “The economic commitment of climate change”. Nature,volume 628, pp 551–557 17 April 2024. Retracted due to irremediable flaws, 3^rd December 2025.

3.         John Christy, Ph.D., Judith Curry, Steven Koonin, Ross McKitrick, Roy Spencer, “A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate”, Report of the Climate Working Group to U.S. Energy Secretary Christopher Wright, USA Department of Energy, July 23, 2025

4.         Mengmeng Cao, Kebiao Mao, Sayed M. Bateni, Jing M. Chen, Essam Heggy, Jong-Seong Kug, Xinyi Shen, “Evaluation and prediction of the effects of planetary orbital variations to earth’s temperature changes”. 
International Journal of Digital Earth , vol18, 6^th April, 2025 https://www.tandfonline.com/doi/full/10.1080/17538947.2025.2487058#abstract

5.         NASA Earth Observatory, “Solar Radiation and Climate Experiment. 21stJanuary 2003 https://earthobservatory.nasa.gov/features/SORCE/sorce_03.php

6.         David Coe, Walter Fabinski, Gerhard Wiegleb. “The Impact of CO2, H2O and Other “Greenhouse Gases” on Equilibrium Earth Temperatures.” International Journal of Atmospheric and Oceanic Sciences. Vol. 5, No. 2, 2021, pp. 29-40. doi: 10.11648/j.ijaos.20210502.12, August 23, 2021.

7.         Edwin X Berry, “Human CO2 Emissions Have Little Effect on Atmospheric CO2”, International Journal of Atmospheric and Oceanic Sciences. Vol. 3, No. 1, 2019, pp. 13-26. doi: 10.11648/j.ijaos.20190301.13, June 4, 2019 

8.         Camille Veyres, Jean-Claude Maurin, Patrice Poyet, “Revisiting the Carbon Cycle”. SCC Open Access Vol. 5.3 2025, pp135-185, ISSN 2703-9072.

9.         Dieter Schildknecht, “Saturation of the Infrared Absorption by Carbon Dioxide in the Atmosphere”. International Journal of Modern Physics B, August 6, 2020, 

10.      Richard Lindzen and William Happer, Physics Demonstrates that Increasing Greenhouse Gases Cannot Cause Dangerous Warming, Extreme Weather or Any Harm.” CO₂ Coalition, 7th June 2025. https://co2coalition.org/wp-content/uploads/2025/06/Lindzen-Happer-GHGs-and-Fossil-Fuels-Climate-Physics-2025-06-07.pdf

11.      Chris Landsea and Eric Blake, “Was 2020 a Record-Breaking Hurricane Season? Yes, But. . .”, Inside the Eye, Official Blog of the National Hurricane Center, USA, 20^th June, 2021https://noaanhc.wordpress.com/2021/06/30/was-2020-a-record-breaking-hurricane-season-yes-but/

12.      John Raine and Bryan Leyland, “A Realistic Energy Future”, Breaking Views NZ 25^th August 2025, https://breakingviewsnz.blogspot.com/2025/08/john-raine-bryan-leyland-realistic.html

13.      The Centrist, “The $1,440-per-tonne climate illusion: Auckland’s food scrap bins don’t add up”, May 11, 2025. https://centrist.nz/the-1440-per-tonne-climate-illusion-aucklands-food-scrap-bins-dont-add-up/