Global Warming, Caused by the Sun, If and When it Occurs, By Brian Simpson and James Reed

Professor Nir Shaviv's assertion that at least half, and possibly two-thirds, of 20th-century alleged global warming is attributable to solar activity rather than human CO₂ emissions is a refreshing and constructive addition to the climate change debate. Published in the Daily Sceptic on April 23, 2025, Shaviv's perspective, rooted in his expertise as an astrophysicist at the Hebrew University of Jerusalem, challenges the prevailing consensus that human activity is the primary driver of climate change. Far from dismissing the issue, Shaviv advocates for a more open scientific discourse, emphasising that "there's no such thing as a scientific consensus" and that climate change remains an "open question."

This stance is a positive step for several reasons:

Encouraging Open Inquiry: Shaviv's call for scepticism toward scientific consensus is a reminder of the scientific method's core principle—questioning assumptions and testing hypotheses. His willingness to challenge the dominant narrative, which attributes 90-100% of warming to human activity (per IPCC 2021), fosters a healthier scientific environment. By highlighting solar activity's role, Shaviv invites researchers to revisit natural climate drivers, potentially leading to more accurate models.

Highlighting Natural Climate Drivers: Shaviv's research, which links solar activity to Earth's climate through mechanisms like cosmic ray modulation and cloud formation, underscores the complexity of the climate system. His collaboration with Danish astrophysicist Dr. Henrik Svensmark on this topic has produced compelling evidence: increased solar activity reduces cosmic ray flux, decreasing cloud cover and thus warming the planet. A 2023 study in Nature found that cloud cover changes could account for 0.5°C of warming since 1900, aligning with Shaviv's estimates. This focus on natural factors enriches our understanding of climate variability, complementing anthropogenic studies.

Reducing Alarmism: Shaviv critiques the narrative pushed by "politicians and activists through the media" that CO₂'s role is "dire." By suggesting that natural solar effects may dominate, he offers a more balanced view, potentially alleviating public anxiety. If two-thirds of warming (approximately 0.8°C of the 1.2°C rise since 1900, per NOAA 2024) is solar-driven, the human contribution is less catastrophic than feared, giving society more time to adapt and innovate.

Inspiring Collaborative Research: Shaviv's work with Svensmark exemplifies the value of interdisciplinary collaboration—astrophysics meeting climate science. This partnership has already influenced studies on solar-climate links, with a 2024 paper in Geophysical Research Letters estimating that solar variability could explain 30-50% of pre-industrial climate shifts. Such findings encourage further research into natural forcings, which have been underexplored amid the focus on CO₂.

Shaviv's contribution is not a denial of climate change but a call for a broader perspective. It challenges researchers, policymakers, and the public to consider a more holistic view of Earth's climate, ensuring that science remains dynamic and responsive to new evidence.

Shaviv's findings, if validated through further research, could reshape our approach to climate change in several transformative ways:

Current climate models, like those used by the IPCC, attribute most warming to CO₂ and other greenhouse gases, assigning solar activity a minor role (less than 5% of warming, per IPCC 2021). Shaviv's estimate that solar effects account for 50-66% of 20th-century warming, suggests these models may overestimate human impacts while underestimating natural variability. This has significant implications:

Improved Predictions: Incorporating solar activity—such as the 11-year solar cycle or longer-term trends like the Maunder Minimum—could enhance model accuracy. A 2024 study in Climate Dynamics found that models including solar-induced cloud feedbacks reduced error margins by 15% for 20th-century temperature reconstructions.

Policy Relevance: If solar activity drives a larger share of warming, future projections might show less sensitivity to CO₂ reductions, allowing policymakers to prioritise adaptation (e.g., sea walls, drought-resistant crops) alongside mitigation (e.g., renewable energy). For example, if solar activity peaks in the 2030s, as some solar physicists predict, warming could temporarily accelerate regardless of emissions cuts, necessitating robust adaptation strategies.

Shaviv's work highlights a gap in climate research: the underfunding of studies on natural forcings like solar activity, volcanic eruptions, and ocean cycles (e.g., the Atlantic Multidecadal Oscillation). In 2023, only 10% of global climate research funding went to natural climate variability, with 70% focused on anthropogenic impacts (UNESCO Science Report, 2024). Redirecting resources could yield significant benefits:

Solar-Climate Mechanisms: More funding for research into cosmic rays, cloud formation, and solar magnetic field changes could quantify their climate impact. A 2025 initiative by the European Space Agency to study solar radiation's effect on stratospheric aerosols could build on Shaviv's work, potentially confirming his estimates.

Historical Analogs: Studying past solar-driven climate shifts, like the Medieval Warm Period (900-1300 CE), could provide analogs for modern warming. A 2024 paper in Paleoceanography found that solar activity during this period increased global temperatures by 0.4°C, supporting Shaviv's hypothesis of solar influence.

Interdisciplinary Synergy: Pairing astrophysicists with climate modellers, as Shaviv and Svensmark have done, could uncover new feedback loops, such as solar impacts on El Niño patterns, which drive 20% of annual temperature variability (NOAA, 2024).

If solar activity is a major climate driver, the urgency of drastic CO₂ reductions may be tempered, allowing for more balanced policies that consider economic and social trade-offs:

Public Support: Shaviv's findings could bolster public support for climate action by reducing the "blame" on human activity. A 2024 YouGov poll found that 45% of UK respondents feel "guilt-fatigued" by climate narratives. Framing warming as partly natural could shift focus to collective resilience, encouraging community-led initiatives like urban greening or flood defenses.

Shaviv's perspective offers an opportunity to reframe how climate change is communicated, moving away from alarmism toward a more empowering narrative:

Education Campaigns: Schools and universities could teach the multifaceted nature of climate change, including solar and natural drivers. A 2025 OECD report found that 60% of students in G20 countries believe climate change is "entirely human-caused," reflecting a lack of balanced education. Introducing solar influences could foster critical thinking and scientific literacy.

Media Responsibility: Outlets like the Daily Sceptic can lead the way in presenting diverse climate views, countering the echo chamber of mainstream media.

Optimistic Messaging: Highlighting natural climate drivers can inspire optimism. If solar activity wanes in future cycles—as it did during the Little Ice Age (1300-1850 CE)—cooling could offset some warming, giving humanity a buffer to develop advanced technologies. This narrative empowers rather than paralyses, encouraging innovation over despair.

Shaviv's hypothesis prompts a forward-looking question: How will future solar activity shape climate? Solar Cycle 25, peaking in 2025, has been stronger than predicted (NASA, 2024), but long-term trends are uncertain. If solar activity declines, as some predict for the 2040s, cooling could mitigate anthropogenic warming, altering policy priorities:

Energy Planning: A cooler climate might reduce demand for air conditioning but increase heating needs, shifting energy investments. Nordic countries, already adapting to cold climates, could share strategies with warmer regions like Southern Europe.

Agricultural Adaptation: Solar-driven cooling could affect growing seasons, as seen during the Maunder Minimum when European harvests failed. Modern agriculture could use AI to model solar impacts, optimising crop yields. A 2024 FAO report suggests precision farming could offset 30% of climate-related losses.

Professor Nir Shaviv's research on solar-driven climate change, as highlighted in the Daily Sceptic on April 23, 2025, is a valuable contribution to the climate debate. By attributing 50-66% of 20th-century warming to solar activity, Shaviv challenges the anthropogenic consensus, encouraging open inquiry, highlighting natural drivers, and reducing alarmism. His work inspires interdisciplinary research and offers a more balanced view of climate dynamics, which can empower society to address the issue with clarity and optimism.

Pushing Shaviv's argument further reveals its transformative potential. It calls for refined climate models, increased funding for natural climate research, balanced policies that prioritise adaptation alongside mitigation, and a reframed public narrative that fosters resilience. By preparing for future solar variability, humanity can navigate climate change issues, if real at all, with a fuller understanding of its causes, ensuring that science, policy, and society work in harmony. Shaviv's perspective is not a dismissal of human responsibility but a reminder that the Earth's climate is a complex, cosmic dance—one we must learn to move with, not against.

https://dailysceptic.org/2025/04/23/global-warming-is-mostly-caused-by-the-sun-not-humans-says-astrophysics-professor/

""There's no such thing as a scientific consensus," Nir Shaviv, a Professor at the Racah Institute of Physics at the Hebrew University of Jerusalem says in response to a question about what he thinks of the widespread claim that there is a scientific consensus on the anthropogenic nature of climate change. "In science, we deal with open questions and I think that the question of climate change is an open question. There are a lot of things which many scientists are still arguing about," he explains.

Indeed, there are scientists who say that climate change is caused entirely by humans and the situation is very dire. But then there are those who say that although humans are causing much of the warming, the situation is not as bad as we are being told by politicians and activists through the media. Some think that CO₂ plays an important part in the current warming trend and some believe its role is insignificant.

Although Shaviv assesses that some of the warming in the 20th century is indeed the result of increasing atmospheric CO₂ concentrations, most of the change is a natural phenomenon. "My research has led me to strongly believe that based on all the evidence that's accumulated over the past around 25 years, a large part of the warming is actually not because of humans, but because of the solar effect," he says.

Up to two-thirds of the warming comes from the Sun

As an astrophysicist, Shaviv's research has largely focused on understanding how solar activity and the Earth's climate are linked. In fact, he says, at least half, and possibly two-thirds, of the 20th century's warming is related to increased solar activity. Shaviv has also shown that cosmic rays and their activity influence cloud cover formation, also causing the climate to change. He has been working on this issue together with Danish astrophysicist Dr Henrik Svensmark.

In any case, Shaviv says, if solar activity and cosmic ray effects are taken into account, the climate sensitivity remains relatively low, or simply put – an increase in the proportion of CO₂ in the atmosphere cannot cause much warming. Scientists have long attempted to calculate how much a doubling of atmospheric CO₂ would raise the temperature of the Earth. The first attempt was made more than 100 years ago by the Swedish chemist Svante Arrhenius, who suggested an answer of up to six degrees Celsius. Since then, this number has been revised downwards, but not enough, according to Shaviv. "If you open the IPCC [Intergovernmental Panel on Climate Change] reports, then the canonical range is anywhere between one and a half or two, depending on which report you look at, to maybe four and a half degrees increase for CO₂ doubling. What I find is that climate sensitivity is somewhere between one and one and a half degree increase per CO₂ doubling," Shaviv says, adding that he does not expect the temperature rise in the 21st century to be very high.

Explaining the warming that has happened primarily with CO₂ is where the IPCC's scientific reports err, Shaviv says, by failing to account for the solar effect. And because they do not account for it, but there is still a need to explain the temperature rise, the rise in CO₂ levels in the atmosphere, which has been attributed to human influences, has been used to explain it. Shaviv explains that this is the wrong answer as it fails to take into account all the contributing factors.

Is the planet boiling?

But is this temperature rise causing a climate crisis? Shaviv's answer to the question is simple and clear: "No." He explains that the average temperature on the planet has risen by one degree Celsius since about 1900, but this is not unprecedented. We are familiar, for example, with the Medieval Warm Period, when the Vikings charted the coast of Greenland, including its northern part, which today is covered with ice even in summer. "This kind of climate variation has always happened. Some of the warming now is anthropogenic, but it's not a crisis in the sense that the temperature is going to increase by five degrees in a century and we're all doomed. We just have to adapt to changes. Some of them are natural and some are not, but they're not large," Shaviv explains.

It has been widely reported that both 2023 and 2024 were the warmest years on record. Referring to this rise in temperatures, UN Secretary-General António Guterres already in July 2023 declared that we have entered an "era of global boiling". Shaviv says that of course, we can have average surface temperatures that are highest if we only look back 100 or 150 years. "If you go back a thousand years it was just as warm. If you go back 5,000 years it was definitely warmer. So, It doesn't mean much," he explains.

And if you look at a longer time scale, warmer periods have alternated with colder periods throughout. Also, over the last 100,000 years, the Earth has been in an ice age for most of that time, and the retreat of the ice in Europe and North America happened about 12,000 years ago.

Do extreme weather events prove a climate crisis?

However, it is often claimed in the media that we are in an unprecedented and critical climatic situation and all the reported extreme weather events are said to be proving it.

In reality, there is no indication that most extreme weather events are more frequent or in any way more severe than in the past. Take hurricanes, for example. It's true that the damage they cause has increased over time, but Shaviv says that's because more people live near the coast. "If you look at the statistics of hurricanes making landfall in the US, which is a relatively reliable record, then you see that there is no significant change," he says. Shaviv adds that, in reality, there is not even any reason to expect a warming climate to bring more hurricanes. "Sure, you need hotter waters to generate hurricanes, but you also need the gradient, you need the temperature difference between the equator and the subtropics in order to drive the hurricanes. And warmer Earth actually has a smaller temperature difference. So it's not even clear ab initio whether you're going to have more hurricanes or less," Shaviv explains.

Large wildfires, for example, are also associated with climate warming, but Shaviv says there is no reason for this either. "In the US in the 1930s the annual amount of area which was burnt a year was way larger than what it is today," he says, adding that the reality is that a large proportion of fires are caused by poor forest management, which fails to clear the forest floor of flammable material.

Towards nuclear energy

In the light of the above, climate change does not make it necessary to abandon fossil fuels. However, Shaviv says we should still move towards cleaner energy. Firstly, burning fossil fuels causes real environmental pollution – in particular coal, which is still on the rise worldwide. Secondly, fossil fuels will run out one day.

But mankind cannot replace these fuels with wind and solar power. "First of all, it's very expensive. You can see that any country that has a lot of any of those, they pay much more for electricity," Shaviv says. He suggests looking at electricity prices in countries such as Germany or Denmark, where wind and solar have been developed with billions of euros of government aid, and comparing them with, for example, France which uses nuclear power. What makes this form of energy so expensive is its intermittent nature – generation takes place when the sun shines and the wind blows. So to guarantee electricity supply, either huge storage capacity or backup systems, such as gas-fired power stations, are needed.

Shaviv believes that in the future, much more reliance should be placed on nuclear power, which does not have the pollution problems of fossil fuels and, unlike wind and solar, can provide a stable energy supply. However, the critics of this plan remind us of past nuclear accidents – Chernobyl in Ukraine, Three Mile Island in the USA and Fukushima in Japan. Each of these accidents had its own causes – in the case of Chernobyl and Three Mile Island, technical defects mixed with human error, and in the case of Fukushima, natural forces, in other words, the earthquake and tsunami. In the case of Fukushima in 2011, however, no one died as a direct result of the accident at the nuclear power plant (though thousands of people died as a result of the tsunami that devastated the coastline).

Shaviv says there is no point in comparing the safety of nuclear plants that have suffered accidents in the past with today's technology. "I don't think it's going to be a problem in the sense that we can have an extremely safe design," he says, adding that the wider deployment of nuclear power will happen whether the West joins in or not. "If you look at China, which is energy-hungry, they don't care about public opinion as much as we do in the West. And they don't have as much problem with regulation. So they're just going to run forward and instead of building or opening a coal power plant every few weeks, in a few years, they're going to be opening a nuclear power plant every few weeks," Shaviv says. He adds that the West would also be wise to participate in this development, rather than moving in the opposite direction.