Recent weeks have seen the biggest change for at least 15 years to future climate-change estimates. The mainstream media is having great difficulty in dealing with this.
A large part of the problem is that the mainstream media, together with most of the population, is not well equipped when it comes to understanding the science of climate and climate change. It has been easier for many years for the mainstream media to simply shout and re-shout the same cataclysmic and superficial headlines.
Those who do enter the fray from a position of reasonable knowledge know that they will be categorised as either sceptics or alarmists. Trying to have an informed debate free of superficialities as to the alternative scenarios of what lies ahead, has been close to impossible.
So, what is the big change in the climate change debate headlined in this article?
The answer is that the influential scientists who, on behalf of the IPCC, estimate future emissions, have said that we have been placing too much weight on outcomes that, if not always implausible, are now clearly implausible. This is going to have a big influence on the forthcoming IPCC-7 reports which supersede the current IPCC-6.
It is also going to have a big impact on risk assessment and management here in New Zealand.
First of all, it is important to understand the role of the IPCC, of which the full name is ‘Intergovernmental Panel for Climate Change’. It is a body of the United Nations.
The IPCC comprises some hundreds of scientists, who largely work pro bono in their home countries on IPCC matters, alongside their professional employment, typically for universities or government research organisations.
The task of the IPCC is to assess the current state of knowledge in regard to current and future emission levels and the consequent atmospheric levels of greenhouse gases.
The IPCC also assesses the effect of various policies on these greenhouse-gas levels, but steers clear of specific policies that should be followed.
The IPCC does not itself undertake research. Rather, it assesses the broad implications of research undertaken by others.
When it comes to the politics of what policies should be followed, it is the UNFCCC (United Nations Framework Convention for Climate Change) that deals with this. It does this largely through the COP (Conference of Parties) get-togethers held each year somewhere in the world, with every year a different location.
These COP get-togethers are attended by more than 50,000 people, including Government officials, activists and media. Most of the time It is pure theatre where the attendees try to work out what the rest of the world should do.
The current key agreement of the COPs, leading through to the UNFCCC, is the Paris Agreement formulated at the 2015 COP in Paris.
Coming back to the current change in thinking by the IPCC scientists, the key issue is that the IPCC-5 and IPCC-6 worst case scenarios, referred to as RCP8.5 and SSP5-8.5 respectively, should be ‘retired’.
Hereafter, I refer to both of these scenarios as RCP8.5 as they have the same scientific metrics.
The key assumption within both of these scenarios is that by 2100 the greenhouse gas levels would create 8.5 watts per square metre of radioactive forcing across the globe. SSP5-8.5 adds more verbiage in relation to what such a world may look like, but the science is the same.
The first point to recognise is that RCP8.5 was never intended as a projection likely to occur. Rather, it modelled the worst possible outcome under extreme circumstances.
Underlying assumptions of RCP8.5 include that global emissions would increase three-fold during the current century. This was in turn based on a global population reaching 12 billion people, plus ten-fold increases in coal-burning, plus a lack of new technologies, and with minimal attempts to reduce emissions.
The RCP8.5 scenario leads inexorably to a likely cataclysmic global warming of approximately five degrees centigrade. However, even this has been widely misunderstood in communication.
The five degrees warming was relative to a pre-industrial baseline of 1850-1900. If measured relative to current 2026 temperatures, it was a scenario for a further increase of 3.6 degrees, given that temperatures have already increased by around 1.4 degrees centigrade since the 1850-1900 baseline.
Somehow, RCP8.5 came to be known as the ’business as usual’ (BAU) projection which was never the intention of the IPCC scientists who devised it. Rather, it was an extreme theoretical projection of what could happen under a set of what are now ridiculous assumptions.
Here in New Zealand, RCP8.5 is widely used to underpin assessments of environmental risk. Large listed companies are legally required to file annual climate statements that must include risks based on the RPC8.5 standards.
NIWA uses RPC8.5 in its climate hazard projections. Local government uses use it to test infrastructure resilience, adapt spatial plans, and develop long-term risk management. All of this now needs to be reassessed using realistic scenarios.
This is not to say that climate change, with the official retirement of the RCP8.5 scenarios, is now somehow unimportant. That seems to be President Trump’s perspective.
That is not what the new reality tells us.
What the numbers now tell us, is that if current global policies on greenhouse gas moderation are followed, then by 2100 it is likely that temperatures will increase by a further 1.2 to 1.6 degrees. This is based on global emissions of carbon dioxide maxing out at around the current 38 billion tonnes per annum, and total emissions of other greenhouse gases also stabilising at current levels.
If countries impose additional policies that they have in principle committed to, but have not yet put in place, then current temperatures are still likely to increase initially through to 2050 with an increase of about 0.6 degrees, but then stabilising thereafter and eventually declining to current temperatures on a multi-century basis. This too is based on carbon dioxide emissions maxing out at around 38 billion tonnes per annum but with a greater rate of subsequent decline.
If we want to state what the global effect of humans is likely to have been since the 19th Century industrial revolution, then we need to add 1.4 degrees Centigrade to all of these numbers. That would mean an increase since the 18th century industrial revolution through to 2100 of 2.6 to 3.0 degrees centigrade.
Of course there is still no certainty with any of these numbers. However, science does tell us with confidence as to what are the wavelengths of infrared energy that carbon dioxide blocks out, and similarly for methane. So, we are not travelling blind.
With methane, there is evidence that methane also blocks inward energy. If correct, this means we are over-estimating the greenhouse effects of methane.
One thing these latest numbers don’t tell us is the effect of President Trump’s energy policies on reducing the American trend to renewable energy, and the global implications thereof. However, President Trump will only be in place for another 2½ years.
Thereafter, it is reasonable to assume that America might get back on track to resource sanity, particularly in regard to coal versus renewables. Without that American sanity, temperature estimates will increase.
Here, I share my own experiences of observing global warming from a lifetime of mountain activities.
When I was alpine guiding in the early 1970s there was no such thing as the Hooker Lake, the Mueller Lake, or the Tasman Lake within Mt Cook National Park. Those massive lakes, now held back by glacial moraine, were a mass of ice laid down some hundreds and thousands of years ago.
These effects have occurred globally.
For example, in 1974/75 my journeys included a year of adventuring in the Andes, from Peru to Tierra del Fuego. In South Patagonia our group came upon an unnamed valley which I called Valle Olvidado. This is now the official name, with ‘olvidado’ meaning ‘forgotten’.
There was no evidence that anyone had ever been there and we tried to leave it that way after a month of mountaineering. The valley contained a big glacier. Fifty years later there is now a large lake more than two kilometres long at the foot of a considerably smaller glacier. An internet search using ‘olvidado’ and ‘glacier’ records the rate of change.
In 1977 I was on Mount Everest. Current photos show the Base Camp area as a very different place to what we encountered. Much of the ice has gone. It is happening everywhere.
To get back to what this all means in New Zealand, we are not facing a cataclysmic situation. Since the Pakeha came to New Zealand we have experienced a 1.4 degree centigrade increase in temperatures, hardly knowing for most of the time it was occurring.
If temperatures increase by another 1.4 degrees we will manage that too, with the same fortitude we have used in the past. Plant varieties and pests may change, but we will find solutions, albeit with some pain at times. Summer air-conditioning may become more common. Winter-cold will become somewhat less of an issue. Storms will occur much the same as they have always occurred, maybe but maybe not with more power.
For young people it is particularly important that they understand the future does not need to be cataclysmic from climate change. There is a future lying in front of us waiting to be delivered through hard work and rational decisions.
The scenarios referred to in this article are available at https://gmd.copernicus.org/articles/19/2627/2026/
*Keith Woodford ONZM was Professor of Farm Management and Agribusiness at Lincoln University for 15 years through to 2015. He is now Principal Consultant at AgriFood Systems Ltd. You can contact him directly here.
32 Comments
I know (most) people like to be optimistic and the preliminary explanation was good but i fear that the ending ignores too much, not least of which are tipping points and planetary boundaries....the 2nd 1.4 deg (if that is what occurs) will not be a simple progression of the previous 1.4 deg
Keith was given some reading on that - which he won't have done (or the last sentence wouldn't have been there).
My guessing is that he will continue not to - nice fellow, honest in his way, but avoidance is avoidance is avoidance.
He is not alone either - much of academia stops short of examining its conscience re personal 'income' vs student 'debt' vs societal legacy. It is understandable, but I suggest is less excusable.
In real terms, we face a compound predicament. Climate is but one of the inputs, and feed-back-loops betwixt them is the killer.
Yeah. To misquote Bush 'It's the tipping points, stupid'
.
Thank goodness the future ends at 2100.
As the lead author of the new scenarios says, "8.5 can still be achieved, but for the wrong reasons"
29:30 https://www.youtube.com/watch?v=L8EuYhK-ilU&t=58s
Population and the amount of carbon we are projected to burn have been demoted, although that could be derailed by the number of right wing idiots and religious maniacs obtaining power globally, while the "wrong reasons", unknown tipping points and climate sensitivity ignored. Additionally there is the assuption CCS will be adopted on massive scale, without which 1.9 and 2.6 are also retired, because they're in the rear view mirror!
Meanwhile the ultimate "equilibrium global warming for today’s GHG amount is 10°C, which is reduced to 8°C by today’s human-made aerosols. Equilibrium warming is not ‘committed’ warming; rapid phaseout of GHG emissions would prevent most equilibrium warming from occurring."
https://academic.oup.com/oocc/article/3/1/kgad008/7335889?searchresult=…
Seems the growth cult have managed to infiltrate and steer civilisation through the IPCC. Always bound to happen.
Yes it was - and that parallels the silencing of science across the western world. Also parallels the Stanford 'no child allowed to think for themselves' approach to education - uncritical bricks in the wall are what the system requires.
If you compare to when the moa hunters arrived, rather than europeans, you can a least take in to account the Little Ice Age which the IPCC conveniently use as a starting point.
"Raeside's14 comparative studies of Canterbury soils and vegetation indicate that the climate prior to 1200 A.D. was warmer than present day. Summarizing his findings on soil investigations, and other evidence of moa remains in swamps, forestry and pollen studies, and high moraines in the Antarctic, Raeside15 suggests that a fall in temperature of at least 2 C. occurred.
...When the kumara was first introduced into New Zealand, it is probable that its growing would have been attempted after the same manner as in the tropics. There is sufficient evidence to suggest that in the present climate the plants would be unlikely to survive more than their first growing season, after which frosts would destroy them entirely. Because of the more favourable climate in that early period, however, it is suggested that introduction into the warmer northern parts of the country might need to undergo little modification of the island cultivation methods to survive, particularly if the growing season were of longer duration than at present."
Yes, it is possible , perhaps even likely, that the New Zealand climate was warmer than present when the moa hunters first arrived. The reasons for that, if it is correct, are natural variations. Thereafter, it got colder for a few hundred years, once again due to natural variations. The current temperature warming is undeniable but of course there is ongoing debate as to the set of causative factors and their relative importance.
KeithW
Is there "ongoing debate as to the set of causative factors and their relative importance."?
.
There you have the reasoned debate in a nutshell, PT08.
"J.D. Raeside’s 1948 foundational research on Canterbury soils
concluded that temperatures in New Zealand prior to 1200 A.D. were at least 2degC warmer than modern times."
1948 huh?
Yeah, nah. More BS from our resident expert denier!
Modern paleoclimate reconstructions confirm that J.D. Raeside
correctly identified a distinct medieval warming period in New Zealand, but they indicate he significantly overestimated its magnitude.
While Raeside estimated that pre-1200 A.D. temperatures were at least 2deg C warmer
than modern times, modern data shows the anomaly was much milder, peaking between 0.3C 1.0C warmer
than the 20th-century baseline.
https://www.sciencemediacentre.co.nz/2013/04/22/reconstruction-of-2000-…
"New Zealand’s annual average temperature has increased by about 1.1°C to
1.3°C
since the 1961–1990 baseline"
https://www.stats.govt.nz/indicators/temperature/
So um warmer now than your mythical past profile!
Palmtree08 There is plenty of published, peer reviewed bullshit out there for you chap, not just the stuff that meets the IPCC's manmade mandate. Get back to me when we have our historic kumara growing range back.
"Amongst many sources of evidence, research by Heidi Anne Roop on laminated sediments in Lake Ohau, south Canterbury, provides a fine-grained picture of climate variation through the period of Māori occupation (Figure 2). Blocking conditions dominated the Polynesian Warm Period up to the late fourteenth century.
...Climate change seems a plausible explanation for the retreat of gardening, if not necessarily the only one. Kumara will not produce in soil temperatures of less than 150C for five consecutive months, conditions barely met in central New Zealand even today.20 A northward retreat of 150 km on temperature grounds implies a decline in mean annual temperature at sea level of about 10C. Looking at evidence of changing temperatures over the last millennium, it is apparent that an early period, estimated as 0.3-0.50C warmer on average than the twentieth century, was followed by a cold period of similar deviation below the twentieth century average. This is recorded in various sources."
Great to see you now accepting proxy data as a valid measure of past climate. What's next? Quoting Manns multiple lines of proxy data showing rapid global heating?
You're pretty good at quoting BS yourself Profile, including studies from 80 years ago. Why don't you go all in and quote flat earth theory? Kumara growing was obviously never very successful in central NZ evidenced by the fact permanant Pa sites are few and far between. Although potential growing sites have been discovered there's no clues how productive they were before abandonment for whatever reason. The heating trend shown by NZ data is more pronounced as increasing minimum temperatures, something kumara growing isn't going to respond to in marginal districts! The overnight warming trend will assist removing the last permanant ice off the Southern Alps in short order though.
Global heating means good crops of Kumara can be grown in southern England now though.
It is not just proxy data though is it. It is backed up archeological and agricultural data. Mann of course is infamous for removing the MWP from his hockey stick - and splicing proxy and real data together on charts without telling anyone but his Climategate email chums. Last seen misleading jury trials. What a guy.
"it would be nice to try to "contain" the putative "MWP", even if we don't yet have a hemispheric mean reconstruction available that far back".
"There is sufficient evidence to suggest that in the present climate the plants would be unlikely to survive more than their first growing season, after which frosts would destroy them entirely. Because of the more favourable climate in that early period, however, it is suggested that introduction into the warmer northern parts of the country might need to undergo little modification of the island cultivation methods to survive, particularly if the growing season were of longer duration than at present."
https://www.jstor.org/stable/20703913
https://www.legalnewsline.com/state-courts/judge-says-climate-scientist…
When you dusturb any really big system like the global climate, that process destabilises the way said system behaves and variability increases until the changing variable(s) stop moving and a new equilibrium is reached.
Climate temperate rise is a slow moving thing by human standards, but the system instability that gets expressed as more frequent, more extreme weather events is a lot more visible and is a real, here-and-now problem.
The human problem is the politicisation and parasitisation of the whole business by special interest groups that makes clarity hard and sensible public debate apparently impossible.
We're our own biggest problem.
Yes we are - it is becoming obvious that sapience doesn't develop fast enough (oh, delicious irony).
So en route from single-cell ignorance, it gets smart enough to irrupt, using planetary-resource draw-down to do so. But it doesn't get smart enough to see the consequences ahead of time. So it collapses. Perhaps remnants go to the next level intellectually, understanding that they cannot consume as during the irruption. But perhaps not.
Yeast don't see it coming either.
Like most on this site, I am not a scientist and can only contribute based on all the reading I have done over the past 20 years. I now have 22 books on the subject of climate change and over that time I have gone from an initial scepticism that however much additional carbon we put into the atmosphere would be sufficient to seriously alter the world's climate to the other end of the scale and now to a middle ground. My latest book is Climate Change Isn't everything by Mike Hulme, Professor of Human Geography at Cambridge University and involved in climate science for over 40 years To paraphrase him, yes, climate change is undeniably real and a serious issue, but it is not an existential threat to life on earth.
To me, arguments over whether it was warmer in the Medieval period are irrelevant. The estimated population was under 400 million while today is is over 8bn, so there are lots of people living where nobody lived before now being affected by extreme rainfall events, rising sea levels, shrinking glaciers and so on.
On the Medieval Warm Period, the Domesday Book only listed some 50 vineyards in England, while today there are over 700. Just saying.
"To paraphrase him, yes, climate change is undeniably real and a serious issue, but it is not an existential threat to life on earth."
Depends how far down the complexity ladder the definition life on Earth encompasses I guess? I'm pretty sure there will be single cell organisms flourishing around hydrothermal vents on the sea floor in 1000 years. The odds of survival decrease the further up the complexity chain, depending how far the human organism wrecking ball is allowed/able to, swing.
Although I won't be here to experience it, I spend considerable time thinking about future scenarios looking out to 500 years ad even beyond. There is no scenario that makes sense without a stable (or gently oscillating) population and a stable global ecosystem. I tend to assume that nuclear fusion will have been solved. I also think that renewable energy will be totally dominant. The greatest risk to humankind is likely to be nuclear Armageddon. I envisage a population somewhat smaller than the current one. I tend to assume that our global social systems will be very different than is currently the case.
KeithW
Keith,
"I also think that renewable energy will be totally dominant". From what I read, the EROI of wind and solar once all costs are accounted for, is too low. I have a paper here The Hidden Costs of Delivered renewable Energy which sets out these issues. Eg. Curtailment costs when a grid cannot absorb the available renewable enrgy. This issue can be seen clearly in the UK where this cost is increasing yearly and was already over £4bn in 2022. Source National Grid ESO. Harmonics and noise. It is estimated that some 8% of generated power is lost this way.
A question that I haven't seen answered is this; will it be possible to build windfarms and solar arrays when we no longer have fossil fuels?
linklater01
Yes, I believe that renewables without fossil fuels is already possible in a commercial setting with existing battery technology. This was probably not possible five years ago.
KeithW.
Any references for that, Keith?
I've lived off-grid, frugally and efficiently, for many years - but I have never heard of a PV panel making PV, a wind-turbine manufacturing a turbine, or a dam making a dam. Or, for that matter any of them making batteries.
For a start, long-haul flying is very out, and short-haul still fraught; you are still carrying the battery-weight at the end of the flight. Same with trucking - you're no emptying your tank en-route (although admittedly your battery/motor is somewhat more efficient ex charging. Space travel is out. Nitrogen fertiliser is out (in present form).
Renewables is a glib term - they are really rebuildables. The question becomes; can they be rebuilt ex FF? Nobody, to my knowledge, has proven that they can.
I referred to what is possible. Currently there is no need for PV materials to be made with fossil-free energy. But the technology is now there.
KeithW
Keith,
Can i refer you to https:robertbryce.substack.com/p/the-iron-law-of-power-density-part
I remain doubtful that we will be able to replicate our current society with solar and wind in the absence of ffs but there is much that we could easily do without while leading perfectly decent lives. Of course, I may be totally wrong and technology may allow us to continue as we are, but would that be altogether a good thing?
linklater01
I have gone to Robert Bryce's archive and that has helped me understand why renewables are criticised for having a low EROEI.(The link you provided was problematic but google got me there.) As you will well know, EROEI measures the ratio of energy gained relative to energy supplied including construction energy. My own perspective is that the EROEI of solar is improving, mainly thanks to Chinese technology, but in any case an EROEI of 3.5 is not a disaster. I agree that offshore wind remains problematic from the perspective of construction cost. But solar is different.
I am happy with Robert's focus on nuclear energy as a key part of the future but I remain confident that our technology gains for solar are sufficient for solar now becoming a 'complete package of energy 365 days of the year and 24/7. If that does not happen then various forms of nuclear energy become essential, with fusion and thorium both paying a likely part. Once again I see China leading the way.
Keith
In reply to Keith's "future scenarios" I agree. Climate change is the least of our worries. War fueled by greed and imperialism are by far our greatest threat.
Palmtree08,
I took it as read hat life included mankind.
Our current perspectives align. But even for those who do not share our perspective, there is a need to recognise that the rules are changing.
This comment was meant to be in response to linklater01
KeithW
Thank you for bring this update from the IPCC to our attention Keith.
I'm calling the end of the global warming scamdemic. Next lefty game plan to kill growth, prosperity and progress will be that AI is going to take away our jobs, increase inequality, remove our privacy and destroy democracy.
Growth does not need to "be killed'...it is dying an inevitable death and has been for some years.
Agreed.
But things can be made untrue by merely blaming a 'them'.
Upton Sinclair...
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