Solar Geoengineering Insanity

By Dr Damien Downing, MBBS, MRSB

UK scientists are to launch outdoor field trials of geoengineering experiments as part of a £50 million government-funded programme. There have been various reports that experiments to dim sunlight in an attempt to fight global warming will be given the green light by the Government within weeks, which will make the UK one of the biggest funders of geoengineering research in the world. Trials, which include spraying large quantities of reflective particles into the stratosphere, are being considered by scientists. The Advanced Research and Invention Agency (ARIA)-the UK government agency modelled on DARPA-is backing the plan and has set aside £50 million for projects, to be announced in the coming weeks.

Yet these so-called "climate solutions" come with immense biological, ecological, and ethical costs. Not only are they a dangerous distraction from the work needed to directly address man-made climate change, but they are also a direct threat to human health.

We have known for over a century that cancer incidence is inversely proportional to sunlight exposure [1], and more recent evidence indicates this is true for the major chronic diseases of modern life.

A 2018 Swedish study showed that, in northern Europe at least, avoiding exposure to the sun shortens life expectancy by at least as much as smoking-about two years on average [2]. The protective effect of sunlight applied broadly to cancer, cardiovascular disease, and type 2 diabetes [3].

Ultraviolet light is necessary for manufacturing vitamin D in the skin, and different wavelengths have different affects on mood, mental functioning, the immune system and healing in general. Around 50% of the energy reaching the earth from the sun is in the non-visible infrared waveband, which we now know has profound benefits for all life, including humans. [4,5]

Then in 2024, a large British study titled Higher Ultraviolet Light Exposure is Associated with Lower Mortality [6] analyzed data from nearly half a million individuals in the UK Biobank. It found that a 15% increase in estimated sunlight energy exposure correlated with a 12% reduction in all-cause mortality. An implication of this study is that any geoengineering of the atmosphere that reduces ultraviolet light could therefore be detrimental to health.

Despite such evidence, solar geoengineering is being aggressively pursued not only in the UK but also in the United States, China, and around the world.

In the United States, a government report in 2023 assessed the feasibility of solar radiation modification techniques like stratospheric aerosol injection (SAI). Prominent institutions have conducted and proposed outdoor experiments-raising alarm about unilateral experimentation without public or scientific consensus. U.S.-based think tanks continue to advocate for structured deployment frameworks, despite the acknowledged risks.

China, meanwhile, has expanded research into atmospheric manipulation, including models of aerosol-based sunlight reflection, alongside its vast weather modification program. Chinese researchers have contributed to global scientific literature evaluating geoengineering's potential-again, without sufficient ethical safeguards or international agreements.

Globally, the United Nations and IPCC have acknowledged solar geoengineering in climate reports but warn of "large uncertainties" and "substantial risks" to ecosystems, weather patterns, food systems, and geopolitical stability. The lack of a unified global governance mechanism means rogue or premature deployment could endanger populations without recourse or accountability.

In short: Blocking sunlight is not a solution to climate change. It is a high-risk gamble with our health and our biosphere.