Contributed by Howard Dewhirst, FGS © 2019

Howard Dewhirst is part of a group of Fellows of the Geological Society of London who have challenged the society’s position on human-causation of global warming.

Friends of Science Society spoke with him at the Basic Science of a Changing Climate Conference in Porto, Portugal,  September 2018.

Despite 30 years of effort and many billions of dollars spent, the IPCC (Intergovernmental Panel on Climate Change) and  the world have failed utterly to stop the rise of human CO2 emissions. Is this because people don’t care, or is it becoming more and more obvious that the Anthropogenic Global Warming (AGW) hypothesis is flawed? Warming has undoubtedly occurred and this century is warmer than the last two, but the world’s average temperature has hardly moved since 1998, while CO2 has increased by 30%.

Half of the warming post the Industrial Revolution had already occurred by 1943, before the increase in human CO2 emissions that began around 1950, so what caused this warming?

Since the start of the last century, there have been two periods of warming, the first without increased CO2, the second post 1978, with sharply increasing CO2 emissions. There have also been two periods of cooling/lack of warming, both of which were accompanied by increasing CO2. If CO2 causes warming, the world should have continued to warm since ~1950 when CO2 emissions began climbing higher and higher, but it did not. This discrepancy suggests that the IPCC AGW hypothesis, that human CO2 emissions cause warming, may be wrong.

What the increase in atmospheric CO2 has done, is increase crop yields world-wide, by ~30%, with as yet, few serious side effects; so why do we need to cut emissions now? And if Australia reduced its current 407 Mt CO2 emissions to zero, what difference would it make? World human CO2 emissions in 2017 were 33,444 Mt (= just 4.3ppm gross addition to the atmosphere), with China contributing 9,330 Mt and USA 5,100 Mt.  Australia produced 427 Mt (~= 0.05ppm). And what would its removal cost us? Just look at South Australia where the price of electricity is double what it is in Canberra, and three times the price in the US; and the state’s share of the Australian economy has fallen from 8% in 1986 to 6% in 2017 as more and more factories close; now apply that to the whole country.

Daily we are told that Climate Change disasters are crippling the planet, as weather becomes more and more extreme, but it is not. 2018 is the first year ever, without severe (>F3) tornadoes in USA; Australian cyclone frequency has fallen since 1971, droughts and rainfall are not more frequent or severe, bleaching of the Great Barrier Reef is not increasing, nor are el Niños. Cold oceans absorb CO2 so the warmer the seas get, the less so-called ‘acidification’ there is. Fire damage in California is increasing but not the numbers of fires, suggesting forest management is the problem, as it has been in Australia. The average number of very hot days in USA and Australia is not increasing

Sea level rise at Sydney harbour is a steady 7.5 cm per 100 years, and shows no sign of being affected by increasing CO2. Malaria will not spread as the globe warms, as it is not a solely tropical disease, (the world’s largest known epidemic was in Siberia in 1920s). Alpine glaciers are retreating – and have been doing so since about 1825; global warming began around 1695 at the beginning of the end of the Little Ice Age and sea level rise began around 1795, all well before human CO2 made an appearance.

Arctic sea ice is shrinking (but has not disappeared as famously promised by Al Gore), Antarctic ice is getting thicker and polar bear numbers are increasing, as is Antarctic sea ice. Overall the claimed impacts of human induced CO2 emissions are not happening.

Endlessly we are also told that 97% of scientists agree that human CO2 is the cause of global warming; the analysis was skewed.  Al Gore made it famous in his ‘Inconvenient Truth’ video, but it is a deception. 

There probably is 97% agreement that CO2 emissions are increasing and that the planet has warmed, only dictators get a higher percent of support than that. What is not agreed is that the warming is dangerous and was caused by human CO2 emissions.

Wrapped up in the 97% debate is another even more blatant manipulation of data to give false support to the IPCC AGW hypothesis – Climate Gate. In 2009, a few thousand emails were hacked from the University of East Anglia department that produces one of the five or so sets of international climate data that are used to measure the world’s average temperature.  The most relevant is from Phil Jones ‘I’ve just completed Mike’s Nature trick of adding in the real temperatures to each series for the last 20 years (i.e. from 1981 onwards) and from 1961 for Keith’s, to hide the decline’  What used to be called the Nuclear Winter, was a period of declining world temperature from 1943 to 1978 which the authors of the emails identified as a problem for their IPCC warming story, and which was eventually removed from the record.


Slowly but surely the world’s temperature data sets were massaged to make them fit the IPCC song sheet; called homogenisation, temperature data from earlier years were made colder and data from later periods was made warmer, to give the erroneous impression that the world’s average temperature had always increased since the start of the Industrial Revolution.

The Medieval Warm Period (MWP), which saw the Vikings settle in Greenland as farmers, is well documented and appeared in the First Assessment Report in 1990 of the UN climate panel report (IPCC). In a later IPCC report, the now infamous ‘Hockey Stick’ was featured and also saw the light of day in Al Gore’s video. That representation erased that MWP period and showed temperatures declining slowly from 1000 AD, with a sudden up-tick when CO2 started to increase. This representation is now hotly debated, but it was very effective in the video in selling the idea that it was all human CO2 and all our fault.



Here is how the Medieval Warm Period was represented in the 1990 IPCC report.

Much of the IPCC argument about CO2 driven global warming, is derived from computer models, and it is to honour the routinely wrong projections from these models that other players fudge and fiddle with temperature data. What is truly astonishing is that all but one of the 100 plus models used by the IPCC to sell their story, predict a much warmer future than actually occurs. Yet it is these models that governments use to define/decide climate and emissions policy.

The IPCC’s AGW hypothesis claims that human CO2 alone has upset the balance of the world’s carbon budget, and this alone, drives global warming and climate change; however polar ice core data covering the last 800,000 years shows that atmospheric CO2 always responds to changes in temperature, in other words atmospheric CO2 is a result of global warming/cooling, not the driver.


This is the inconvenient fact which all of the data manipulation above is designed to counteract. And it is not just the recent past that is inconvenient as the AGW idea can’t explain why the Ordovician/Silurian ice age took place when atmospheric CO2 was ten times higher than today, nor for the Late Jurassic ice age when CO2 was 6 times higher. Nor does it explain how CO2 rose 25 ppm from the beginning of the Holocene while the average temperature declined. The geological record is endlessly clear, CO2 does not cause warming – unless you want it to, and are prepared to ignore or manipulate inconvenient facts.

The scientific method shows that “If a theory rules out certain possible occurrences, … it will be falsified if these possible occurrences do in fact occur.” CO2 lagging temperature for over 500 million years falsifies the untested AGW hypothesis again and again.

The latest IPCC report claims that it needs just $2.4 trillion per year for 30 years to ‘prevent’ climate change, this is the prize money that keeps the global warming/Climate Change gravy train lubricated. And their failure to achieve any reduction in emissions despite 30 years of effort suggests that they will not succeed in the future, no matter how much money is spent.

The question is, where have these IPCC based predictions ever been correct?

All models predict warmer temperatures than occur, but less than AGW Hypothesis (it I NOT a theory) projects

Models predict tropical tropospheric warming which has never been detected

Models fail to hindcast or forecast any multi-decadal oscillations such as el Nino

Model projections fail to agree with any balloon and satellite temperature data

Models fail to explain warming pre-1943 when human CO2 negligible, cooling from 1943 – 78 and from ~1998 when CO2 was increasing

Models fail to explain high CO2 during interglacials and subsequent cooling

Models fail to explain drop in hurricane frequency from ~1969 to 1994

Models cannot explain lack of clear trends in rainfall patterns

Models fail to explain how Human CO2 behaves differently to natural CO2