As I prepared to head down from a climb of Imja Tse (Island Peak) in December 2015, from the huge moraine wall I pondered the dramatic retreat of the ice on the Imja Glacier. This lake, now known as Imja Tsho, did not exist ten years before. Locals are concerned that the vast volume of water now collected below the glacier will one day break it’s lower bank and unleash an alpine tsunami. The mountains to the west are Tawoche and Cholatse. Khumbu, Nepal

Peter Laurenson, May 2019

Climate change – is it down to us? Climate change. Global warming. What’s causing it? Is it even happening?

It’s complicated alright – many variables, many possible ways to interpret them – especially when you throw in the ‘cherry picking’ curve ball – selective focus and interpretation of the data. Some don’t even realise that they’re cherry picking. It’s hard to know what you do or don’t know and, if you rely on social media for your information, then you’re likely to be being fed a self fulfilling reinforcement of what you already believed.

Talking to people can be revealing. I recently talked with an ex farmer who argued that what us humans are doing has very little to do with the climate change we’re seeing. And actually the temperature levels being predicted in the next few decades are similar to what they were back in 900AD, so what’s the problem? Climate change has become an industry based upon twisted facts and self-interest-driven false science.

Well, I also spoke with a Volcanologist, who was aware about that warm spell. He referred to it as the Medieval Warm Period (MVP), understood to have been caused by solar forcing (insolation or heating from the sun), a reduction in cooling from large volcanic eruptions and ocean circulation change – all natural forces and nothing to do with what humans were doing at the time. Remember that in 900AD there were less than 250 million humans worldwide. Today there are more than 28 times as many of us – over 7 billion. The MVP was apparently not global either – while it was warming in the north, down in the southern hemisphere it was less pronounced. The warming we see today IS a global event.

Ah, but there are lies, damn lies and statistics right? Well, here’s my breakdown of what I’ve so far learnt to be the most widely accepted and most credible ‘facts’…

Climate change is normal. Earth naturally goes through warming and cooling events – some far more extreme than others, some global, some regional.

There are multiple causes. Warming and cooling can be caused by a range of forces – solar, volcanic, organic/chemical – and probably some others I still don’t know of.

The underlying problem. There were about 3 billion humans when I was born. Now there are over 7 billion. This will grow to over 9 billion by 2050. Yet our planet and its resources remain finite.

It IS down to us. Unlike other global warming events, this one is human-driven organic/chemical warming. Since the industrial revolution and particularly in the past 50 or so years, this warming has increased at a faster pace than ever identified at any other time in the history of the earth. Rather than natural forces like volcanic events, it is chemicals (carbon dioxide mainly, but also methane and nitrous oxides) from burning fossil fuels, transport, industries such as dairy/beef farming, consumer behaviours that release fluorocarbon, etc; the dramatic depletion of forests; all amplified by wanton over consumption and waste, that have created the conditions resulting in a warming planet this time around.

This global warming event IS different. The vast (and still expanding) majority of the global scientific community, including most of those recognised as the best minds, conclude that the best and still growing datasets show that humans are in the process of inducing a climate change unprecedented for at least 800,000 years and probably 3 million years or more. The climate 3 million years ago is well outside human experience in terms of food production, ecosystem response, or living conditions. Many climatologists and others suspect that the climate experienced in our grandchildren’s lives and possibly even our aging children’s lives will be very different from now and maybe totally unrecognisable.

Our time to act is running out. There are points, called ‘tipping points’, in the climate system – thresholds that, when exceeded, can lead to large changes in the state of the system. We are now approaching such a tipping point – one where climate change will switch from a human-driven (thereby reversible) to a planetary response. At this point the natural domino effects of our planet’s ecosystems will kick in and there’s nothing we will be able to do to prevent further warming. It will be too late for us. Based on current scientific data predictions, the tipping point is about 2 more degrees of warming, to be reached in the next 30 years if we humans don’t get our collective act together.

The planet does NOT need saving, we do. Earth has been through countless climate change events unscathed. But the environment WE need to survive and thrive in does need saving – that is what’s at stake, not the planet.

Act now, it does matter. Immediate and effective action needs to happen globally, coordinated by governments and industries. But when there are so many humans, even little positive actions by individuals, spanning a very wide spectrum, can also make a huge difference. And in the end, it is individuals who vote in governments and buy corporations’ products, stocks and shares.

I struggle mightily with the beliefs of people like the ex-farmer. Even though there is some room for debate, when the stakes are so high, why spend energy trying to refute a need for more sustainable, less wasteful, less polluting, more respectful behaviours (responses needed to effectively address global warming)? Even IF the human impact on global warming was overstated, the worst thing to happen from acting on that line of thought is better use of our scarce resources – which will help to reduce illnesses, poverty and starvation regardless. On the other hand, if humanity elects to follow human-induced climate change deniers and THEY are wrong, then a conducive living environment for humans (and multitudes of other species) is, at the very least significantly diminished, if not destroyed. Why even contemplate taking that risk?!

Peter, I think it unfortunate that you have hijacked the [May] newsletter for political purposes. Your “Climate Change” editorial is a Green/Radical Left political statement on a divisive issue. At best its assumptions are highly dubious. The same or closely similar views are aired endlessly in the main stream media and I don’t think it desirable or appropriate to air them yet again in the newsletter, just stick to climbing.
Regards
Roger Coombs

Hi Roger. My views weren’t politically motivated. My concerns are environmental, social and recreational. As a club of people who love the outdoors I think the issues around climate change are totally relevant to discuss and debate. Indeed our climbing opportunities are being diminished as our planet warms. I’d be interested to read about your alternative views. Which of the assumptions I described are highly dubious and why? What alternative assumptions do you offer that are more robust? What do you think is an appropriate response, if anything, to our warming planet?
Thanks for giving feedback.
Peter

Roger Coombs, ex Fisheries scientist, June 2019

The earth is thought to be about 4.5 billion years old and there has almost certainly been life for 3.5 billion years. Over that vast time span the climate has varied markedly from much hotter than now, e.g. the early carboniferous is thought to have been 8º C hotter, with sea levels more than 100 m higher. During the last ice age it was 5º C lower and the sea more than 100m lower. In historic times the Minoan, Roman and Medieval warm periods were at least as warm as today. During these warmer times humanity flourished, during cold periods such as the Little Ice Age when rivers froze and crops failed, we suffered.

The modern thermometer was invented in 1709 and global records date from around 1880, so all temperatures earlier than this were obtained indirectly e.g. from ice cores using deuterium concentrations. Typically the latter represent averages over decades rather than the minute-by-minute temperatures possible today. Until the last 30 years or so the thermometer measurements were meant for weather forecasting, not climate monitoring, and substantial selection and manipulation is needed to make them suitable for this. There are several different global temperature series produced by different organisations which show similar historical patterns but may differ by up to 0.5º C. Consequently, there is substantial uncertainty about what historical temperatures were. Overall global mean temperature over the last 140 years has likely increased by around 0.8º C and since WW2 perhaps 0.6º C. Given this, are recent changes unusual as Peter claims? Considering the great variability in the past and the uncertainty in the estimates, I think the answer is no, and the ex-farmer’s view is entirely reasonable.

Is it true that ‘the scientific community’ thinks there’s a serious problem? As a scientist, I don’t think that’s true either. Certainly there’s a small clique of activist climate scientists and a much larger body of non-scientist activists (e.g. Al Gore) that push the idea and it’s also true that many scientific societies, such as the NZ Royal Society do, but that’s the executive, not the ordinary members.

Changing climates are thought to have many causes and Peter lists a few. But establishing causal relationships for any of these is extremely difficult with only limited possibilities for properly controlled experiments. In truth, what controls climate is not well understood. It was discovered in the 19th century that the earth would be much colder but for ‘greenhouse gases.’ The idea that the greenhouse effect of carbon dioxide (CO2) is a major factor originated with Svante Arrhenius in 1896 and this was developed in the 1950s by several climatologists. Modern concern about CO2 and other human generated greenhouse gases all comes from computer models, and the observation that CO2 concentrations in the atmosphere have steadily increased at a time when temperatures have increased. But, correlation is not causation and whilst it is likely that CO2 from burning fossil fuels has contributed to recent warming, the catastrophic levels being predicted assume a positive feedback mechanism for which there is no experimental evidence. The claim that there are ‘tipping points’ in the climate system also comes entirely from models. They are a theoretical mathematical idea and there is no evidence that any such events have ever taken place in the earth’s climate. 2º C is an entirely arbitrary number that has no scientific basis that I can find. Climate scientists have made many model-based predictions, none of which have happened, e.g., in 2000 in the UK Dr David Viner predicted that ‘children just aren’t going to know what snow is.’ Unfortunately, local authorities and others took heed of this and failed to plan for snow, which in later years fell in large quantities causing chaos.

CO2 is not a pollutant nor a threat. On the contrary, it is essential to life on earth and its levels have been much higher in aeons past. They have rarely been much lower except that during the last ice age they dropped low enough that life on earth was under threat. The earth has ‘greened’ significantly since CO2 increased.

Human progress has been marked by our increasing use of energy. Where a few hundred years ago most people laboured for long hours growing food to eat, now, in the developed world, a tiny minority of the overall population produce more than enough food for everybody using the energy from fossil fuels to power machinery. The food is grown using less land leaving more for wild lands and wildlife. Prosperous people have more resources to care for their environment and more leisure time to enjoy it. The developing world lags far behind and understandably wants to catch up which leads to Peter’s idea that population growth is the underlying problem. China and India are busily building more and more coal-fired power stations and their emissions are going to continue to increase. Of course this is only a problem if you think that the inevitably higher CO2 levels are going to doom the world. Other things being equal we might expect that, as these countries get more prosperous their birth rates will drop and they too will be able to value and care for their environment better once they no longer struggle to survive from day to day. Indeed, this is already beginning to happen.

There is no evidence that we face catastrophe. The climate will change and people will adapt as they always have. The call to ‘decarbonise’ our economies, if acted upon, will lead to far greater problems than changing climate, with power blackouts and the like for the developed world and people trapped in poverty, with low life expectancy, for developing countries if they are prevented from using energy from fossil fuels.

Editor’s response , June 2019

Roger is a retired fisheries scientist who believes that real/effective conservation has to be driven by more than piecemeal, emotive arguments by minority groups. Views on both sides have validity and there needs to be a sound process by which these can be weighed before firm decisions about what actions are most appropriate can be made. I can’t argue with that philosophy.

Roger points out that much of the ‘science’ that underpins concerns about global warming is based on models, not hard data, and that there is sometimes significant inherent room for uncertainty, error or misinterpretation. Fair point.

I accept that CO2 is a fundamental building block for life and is not, as such, a pollutant. But if too much of it is retained in our atmosphere, that can cause our global temperature to rise to the point where it is indeed a threat – just look at Tuvalu. The claim that earth’s global temperature has been higher than now does not remove concerns about what consequences will result from further warming in the coming decades.

Whatever conditions existed in warmer times past did not include over 7 billion humans and the associated impacts we have on our environment – this is something entirely new.

Roger points out undeniable benefits that humans have enjoyed from harnessing fossil fuels. With respect, I can’t accept the assumption though, that developing countries MUST continue their use of fossil fuels at similar levels in order to escape the poverty trap. Renewable energy sources are now emerging from obscurity and, in some cases, becoming more viable than fossil fuels. China has made big advances in the adoption of renewables. I see the big difference today being that there is now a genuine will to make renewables work for us, that is finally beginning to shout down the voices of fossil fuel lobbyists.

I also don’t agree that it’s only a small clique of activist climate scientists that subscribe to this model-based thinking. Take Professor Steven Hawking and Sir David Attenborough as two fine examples.

These globally revered scientists have been unequivocal in their belief of and concern about human induced global warming. I simply can’t believe that these people are not across what Roger has explained. Yet they still put their faith in the models. And as this cartoon poses, ‘why wouldn’t you?’ I know that’s easier for me to say than for a dairy farmer right now, but whether the threat of global warming is overstated or not, I still can’t get past the need for humans to address pollution of our air and waterways, desecration of our forests, infusion of plastic into our ecosystems, etc, etc, …
So, what do YOU think? Have your say in July!

Roger Coombs, July 2019

To cover all of your response to my article would need another long paper so here’s just a few points. You place a great deal of trust in renewables to replace fossil fuels but wind and solar are, by their nature, intermittent and even hydro can fail when reservoirs aren’t replenished. Wind and solar need backup or storage for when the wind doesn’t blow and the sun doesn’t shine and the backup has to be some more reliable generation method. The technology doesn’t yet exist to store electricity on a large scale despite claims to the contrary. You quote China as making big advances in adoption of renewables but the most recent figures I can find show hydro is by far the biggest component of that, accounting for about 19% of their overall generating capacity. Wind is about 5% and solar 2%. They continue to build coal burning power stations. They are also building nuclear power stations which is the obvious way to go if CO2 really is a problem.

You think that respected figures like theoretical physicist Stephen Hawking and natural history film-maker Sir David Attenborough hold the views they do because they have studied the details. I think this very unlikely. Once upon a time I was also a ‘believer’, I trusted the word of my climatologist colleagues. What changed my mind was reading the papers that the leading proponents had written. But in any case, science does not depend on authority and consensus, it depends entirely on evidence. The measures being taken to combat the supposed danger of climate change threaten to drastically change our way of life. Drastic measures demand compelling evidence, but in the case of climate change this is distinctly underwhelming.

I agree that there are real environmental issues and I think that the vast sums of money being spent on the supposed ‘climate crisis’ would be much better spent on real problems.

Editor’s response, July 2019

Since the June Vertigo I’ve learnt some more about net energy flows and how fossil fuels provide much greater net energy than renewables. As Roger rightly points out, our developed (and developing) economies are greatly dependent on fossil fuels and, assuming current technologies, renewables can’t get close to replacing them. So I now understand better why some, such as Roger, have big concerns about the implications for the fossil-fuel-enabled lifestyles we’ve become accustomed to, if an ‘un-intelligent’ response to the threat of climate change is pursued. While not supporting it myself, I understand why he raises nuclear power as an option too.

So the question is, what is a reasonable and realistic response? Our Government is realising that 100% renewable generated electricity by 2035 is probably not the smartest target to achieve the best outcome. There is a dawning realisation that a bigger picture, encompassing all forms of energy and all carbon generating and reducing impacts, must be understood in order to set the best targets and actions. Some of what Roger raises in his letters help to inform this discussion. Even so, I can’t see why humans should not move in a less environmentally harmful direction, even if the benefits of this will take longer to accrue than climate change ‘alarmists’ claim we have. While we will be reliant on fossil fuels for some time to come, why not work to reduce that reliance if there are environmental benefits in doing so and we do have at least partial alternatives?

Does it ultimately then just come down to what your ‘world view’ is?

My world view, whether or not we’re doomed to globally warmed purgatory, is that there is no defendable excuse to not move towards a more environmentally respectful approach to living anyway. We can do that without flushing our civilised lifestyle baby out with the bathwater. Perhaps if the debate shifted emphasis, it could be less divisive and thereby encourage more cohesive, collective action? Could a shift away from ‘respond to the threat of climate change’, to ‘shift away from short-term focused economic growth at any cost to a more environmentally respectful and sustainable long-term approach to living’, encourage a better human response? It sounds reasonable, but then again, us humans don’t tend to change our ways unless there’s a big hairy threat, or shiny big incentive, right in front of our faces. If the climate change threat is providing that impetuous then, regardless of the holes that can be picked in its rationale, it is still a force of good. Behind its call to action though, responses must be well informed and pragmatic. It does appear that this is what’s finally starting to happen in New Zealand and around the world. Governments, businesses and individuals have moved from discussion and debate to taking tangible, positive actions. Whether this is going to ‘solve’ climate change ‘in time’ or not is one conversation. But climate change or not, at least finally, we’re moving in a more holistically sustainable direction after a period (between the industrial revolution and very recently) where only the God of economic growth has ruled supreme.

Having followed the recent letters about climate change here in Vertigo, the next letter is from Harry Keys, Earth scientist and ex DOC volcanic risk manager. This letter is a summary of a more detailed paper you can access here.

Harry Keys, Earth scientist ex DOC volcanic risk manager, July 2019 

Climate change is important, so it provokes debate.  Earth climate and sea level have always changed. What is important to us is how much the climate suited to us humans will change over time.

Building an understanding about climate change is a global effort. The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 to provide objective, scientific advice on climate change to member governments. This has under IPCC, hundreds of scientists from all over the world in many specialities assess the thousands of scientific papers published each year, fact checking data sets and conclusions to summarise what is known and identify the strength of scientific agreement. A significant proportion of the scientific community are engaged in such work, not simply a small clique of activist climate scientists.

Limitations do not invalidate scientific models about climate change. Climate scientists are unable to perform controlled experiments on the planet to observe results. Instead a combination of observations, comparisons and mathematical models of interactions in the climate system can be used to test hypotheses.

Repeated examination of uncertainty and model comparisons have refined our understanding, with underlying theories either rejected or improved. This inherent self-correcting nature of science contrasts with social media and the internet which do not necessarily distinguish facts from unproven statements.

CO₂ does cause global warming. Testing models against the existing instrumental record indicates that carbon dioxide (CO₂) in the atmosphere must cause global warming, because the models could not simulate what had already happened unless the extra CO₂ was incorporated in them. All other known change drivers like large volcanic eruptions, solar variations, atmospheric and oceanic circulation, and albedo (related to sea ice extent and land use/cover) are adequate only for explaining temperature variations prior to the rise in temperature over the last 30-50 years.

It is crucially important to understand CO₂ impact lag. After spectacular advances of the Fox and Franz Josef glaciers in the 1990s those glaciers have also retreated dramatically. Like most of the world’s glaciers, they have responded to climate change as they have become out of equilibrium with climate. They will continue to do so in a characteristic response to changing climate, whatever the cause.

Like that time lag, global climate change lags behind increased emissions of greenhouse gases including CO_2, methane, nitrous oxide and fluorinated carbons.

Humans are influencing climate change. We have known for 60 years that the measured concentration of CO₂ in the atmosphere has been rising above preindustrial levels. From the mid-1950s it became clear this is due to fossil fuel combustion. Given the long legacy of our emissions of CO₂ in the atmosphere and the thermal inertia of the oceans, we are currently experiencing the climate effects of our fossil fuel use decades ago. It will take decades more (perhaps 40 years) for the impact of our current emissions to be felt in sea level. Whether we view the most important greenhouse gas, CO₂, as a pollutant or not is just semantics. 

Even with uncertainties, human influence on the climate system is now clear. Evidence includes the increasing greenhouse gas concentrations, positive radiative forcing (aka enhanced greenhouse effect) driven by that extra gas, observed warming, and understanding of the climate system with recent advances in model-based climate studies supported by proxy studies of past climate.

Though imperfect, climate change projections are valid. Projections have been a basic thrust of models of climate change science. Early projections of fewer or less intense frosts, receding snowlines and accelerated thinning/retreating of glaciers as temperatures warm, have generally been matched by recent observations. Synoptic weather events and natural variability such as ENSO obscure some trends.

Escalating sea level rise was also an early projection. Sea level has the potential to affect many people living near vulnerable coasts. IPCC conclude that by the early 20th century, the mean rate of sea level rise had transitioned from relatively low mean rates of rise to higher rates, reaching 3.2 [±0.4] mm/yr between 1993 and 2010.

Some climate variations do matter. Statistically significant changes in some kinds of extreme weather and climate events have been observed since about 1950. These include the number of cold days and nights (decreased) and the number of warm days and nights (increased) on the global scale.  There are likely more land regions on Earth where the number of heavy precipitation events has increased than where it has decreased. Studies are starting to suggest that increased greenhouse gas concentrations partially drive some extreme weather events such as tropical cyclones.

Some extreme events and projections are overemphasised by both sides of the debate. Even if some trends and extremes in temperatures, rainfall, etc can no longer be discounted as natural variability, this does not prove that individual events are caused by human-induced global warming. But equally, arguments that weather-related disasters are completely unrelated to climate change often misrepresent the situation too. A projection of increased temperature or reduced snowfall does not mean snow will never fall, or that there will be no extreme snowfalls or periods of extreme cold.

The pace of recent warming is significant. A huge body of climate science has shown that the warming trend over the last 150 years is significant because it is relatively large. It is also proceeding at a rate that appears unprecedented over decades to many millennia. Global temperature has risen from near the coldest to almost the warmest levels of the last 11,000 years in little more than the past century, reversing a long-term cooling trend that began about 5000 years ago. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.

Climate warming increases sea level. Sea levels are projected to rise between 0.55 and 1.25 metres above pre-industrial levels by 2100. The 1986–2005 average IPCC (2018) model-based projections of global mean sea level rise suggest an indicative range of 0.26 to 0.77 m by 2100 for 1.5°C of global warming, 0.1 m less than for a global warming of 2°C. The implication of a reduction of 0.1 m in global sea level rise is that up to 10 million fewer people would be exposed to related risks, assuming no migration or adaptation.  

Climate change impacts can be good and bad. Benefits include improved agriculture at higher latitudes and increased vegetation growth in some circumstances. However, sea level rise, extreme events and threats to water will be expensive to adapt to. Developed economies will be able to afford the costs but there will be opportunity costs in doing so. Poorer countries affected will struggle.  

There is no doubt we need to make faster progress in mitigation of and adaption to climate change. Reduction in emissions is much discussed, and some European countries appear to have made some, but so far there has been no sustained reduction in the growth rate of CO₂ in the atmosphere.

We are bequeathing serious impacts like sea level rise to coming generations, which make it clear that the sooner we reduce fossil fuel emissions the better. Penalising developing countries, or where pastoral food production is more carbon efficient (like in NZ), is not the answer. 

In NZ part of the solution has to involve stronger incentives of various kinds to reduce carbon emissions and increase the use of renewable energy. Advances in technology, like vanadium redox batteries reducing problems with storing renewable energy, will help. We have significant geothermal energy generation already consented to help the transition. Decoupling GDP from emissions appears to be possible.

Get Harry’s full paper here.