When Dr Doug Edmeades, MNZM, (independent soil scientist, managing director of agKnowledge and perhaps the smartest scientist in the country) wrote recently in NZ Farmer about the theory that we are the major cause of climate change, he said: “On this subject I am a sceptic.”
He didn’t ridicule the theory or mock those who believe it. Rather, he carefully explained the reasons for his doubts that our activities are responsible.
He asked: “What caused ice ages in the last 500 million years, long before humans, oil and industrialisation? What caused cooling and warming cycles in pre-industrial times? What triggered the change out of the Little Ice Age 150 years ago? Is CO2 really the problem?”
These are reasonable questions—many echo them when their curiosity turns to climate change, because to examine what is said about it is to discover uncertainties and inconsistencies. If it is truly necessary to fight climate change these uncertainties absolutely must be addressed.
Dr Greg Bodeker is an adjunct professor at the NZ Climate Change Research Institute, Victoria University of Wellington. In commenting on Dr Edmeades’ article he presented evidence in support of the climatic threat to the earth.
He tried to persuade us to take action against climate change. But he ignored the questions Dr Edmeades raised and failed to explain how we cause climate change. Thus he lost the chance of winning us over.
“I want you to make an intelligent, informed decision,” he said, “based on the evidence. Here is some of it.” But there were defects in his evidence, as you’ll see below. These are the major points Dr Bodeker claimed:
- “The last six decades have been successively warmer.” But that is wrong; only three decades, 1980 to 2010, got progressively warmer. From 1950 to 1975 there was cooling, and the current decade so far is no warmer than the 2000s, except trivially by a few hundredths of a degree.
- “Satellites cannot measure surface air temperatures.” But that is wickedly misleading. Two world-famous teams (UAH and RSS) measure atmospheric temperatures using microwave sounding units (MSUs) that have flown on NASA satellites since 1979. The MSU detects the intensity of microwave radiation given off by atmospheric oxygen, from which the temperature of the lower troposphere is calculated. This is uncontroversial.
- “The trend in surface air temperature has been upwards since 1998.” But looking back through the global datasets for up to 25 years or more, the trend is flat. He might say 14 of the 15 warmest years ever recorded have occurred since 2000, but ask him “how much warmer were they?” and he will reply “a few hundredths of a degree,” which does not impress anybody. The truth is that nobody aged less than about 20 to 25 has experienced man-made global warming.
- “Arctic sea-ice is retreating. Since 1979 [when satellite measurements began], Arctic summertime sea-ice cover has decreased by 9-14 per cent per decade”. But he doesn’t mention that there’s robust evidence that the slow decline over just 30 years is natural. In any case, most of the reduction dates from a sudden precipitous decline only eight years ago, caused by strong winds and currents. Certainly there was less ice at times in the early 20th century. Since the record low of 2007, the ice has recovered; in seven of the years there were hundreds of thousands of square kilometres more sea ice; only one year had less. Anyway, none of this is evidence of warming, for the reductions in sea ice were not caused by warmer air. Antarctic sea ice continues to increase steadily.
- “Sea level has risen by about 19cm between 1901 and 2010.” Which is consistent with recent results from Church and White. But he gives no reason to believe this natural long-term rise is caused by human activities.
- “Many Arctic ecosystems have been adversely affected by changes in climate.” Which means warming, of course. He doesn’t specify the adverse effects, but it’s strange that while a little extra warmth arising from a little extra atmospheric CO2 apparently causes some unidentified adversity, those same levels of CO2 are causing a large increase in the growth of northern plants—which most people would consider a flourishing, not an adverse effect.
- “Long-term reductions in glacier volumes have been observed almost worldwide.” But glacial advance is sensitive to precipitation and topography, so observed reductions may not have been caused by atmospheric warming. Indeed, for the last 20 years there has been no atmospheric warming anyway. Recent ski seasons in New Zealand and elsewhere have begun early and been blessed with plenty of snow. Record low winter temperatures in recent years have wreaked havoc with crops and roads and killed people and livestock around the world.
- “Increases in global average surface temperature since the 1950s can only be explained when increases in atmospheric greenhouse gas concentrations are accounted for.” This is an admission that non-sceptical scientists don’t know what caused the warming; they took a guess. Anyway, the observations show that global temperature cooled from 1940 to 1975. He confuses his account by saying there was a small cooling during the 1950s period of warming.
- “As the oceans have absorbed much of the carbon dioxide emitted into the atmosphere, they have become more acidic” … which “threatens polar marine ecosystems and coral reefs.” But recent research shows some corals have strong control over their internal pH levels. Maps of ocean acidification reveal increases occur only in small areas, mostly in the tropics with none at the poles. So far there is little or no observed damage.
- “Changes in climate have adversely affected yields of major crops.” It’s hard to know what he’s talking about here, for global harvests of major crops have increased over many decades and stand at record highs.
- “Stating that ‘CO2 is essential for life on Earth and therefore cannot be responsible for climate change’ (as Dr Edmeades alludes to) is the same as saying ‘water is essential for life on Earth and therefore cannot be responsible for drowning.'” But what Dr Edmeades actually said was CO2 “is a colourless, odourless gas and essential for life on Earth.” He was simply countering the wrong-headed idea that carbon dioxide is a filthy pollution akin to dirty industrial emissions.
- “Changes have been observed in many extreme weather events.” Which implies they will increase. But he must know that the IPCC report on extreme weather events (SREX 2012) reported few increases in extreme events over recent decades and did not foresee higher risks in future.
Dr Bodeker argues that we must take action against climate change because we’re causing it. But we’re not causing it. If he wants us to “make an intelligent, informed decision based on the evidence,” the minimum requirement is to produce evidence.
He shows nothing to compel belief in dangerous anthropogenic global warming (DAGW). He concludes: “It is time, therefore, to move beyond the pointless ‘debates’ on whether human-caused climate change is real.”
Readers will no doubt agree to shun pointless debate but we might mention it was Dr Bodeker who rendered this one pointless. His evidence is flawed and in omitting to show a human cause of climate change his argument fatally abandons reason.
To describe the debate as pointless after participating in it shows impressive scorn towards his own efforts, but then to blame the pointlessness on Dr Edmeades is positively breathtaking.