Plan B Environmental Activists deservedly lose High Court battle over Carbon Target

Breaking News

From Belfast Telegraph & itv.com and Science Matters (my bold)

Lawyers for the charity previously argued the Government should have, in light of the current scientific consensus, gone further than its original target of reducing carbon levels by 2050 to 80% of those present in 1990.

They said the decision not to amend the 2050 target put the UK in breach of its international obligations under the Paris Agreement on Climate Change and was influenced by the Government’s belief that a “more ambitious target was not feasible”.

At a hearing on July 4, Jonathan Crow QC told the court: “The Secretary of State’s belief that he needs to have regard to what is feasible, rather than what is necessary, betrays a fundamental misunderstanding of the scheme of the 2008 Act and must be quashed.

“All of the individual claimants are deeply concerned about climate change.”

The barrister argued the Secretary of State’s “continuing refusal” to amend the 2050 target means the UK is playing “Russian roulette with two bullets, instead of one”.

But, refusing permission for a full hearing, Mr Justice Supperstone said Plan B Earth’s arguments were based on an “incorrect interpretation” of the Paris Agreement.

He said: “In my view the Secretary of State was plainly entitled … to refuse to change the 2050 target at the present time.

In a previous post I wrote that

Taking court action to compel Governments to enforce the Paris Climate Agreement is against the real spirit of that Agreement. Controlling global GHG emissions consistent with 2°C, or 1.5°C is only an aspiration, made unachievable by allowing developing countries to decide for themselves when to start reducing their emissions. ……. Governments wanting to both be players on the world stage and serve their countries give the appearance of taking action of controlling emissions, whilst in substance doing very little. This is the real spirit of the Paris Climate Agreement. To take court action to compel a change of policy action in the name of that Agreement should be struck off on that basis.

Now I would not claim Mr Justice Supperstone supports my particular interpretation of the Paris Agreement as an exercise in political maneuvering allowing Governments to appear to be one thing, whilst doing another. But we are both agreed that “Plan B Earth’s arguments were based on an “incorrect interpretation” of the Paris Agreement.

The UNFCCC PDF of the Paris Agreement is here to check. Then check against my previous post, which argues that if the Government acted in the true spirit of the Paris Agreement, it would suspend the costly Climate Change Act 2008 and put efforts into being seen to be doing something about climate change. Why

  • China was praised for joining the emissions party by proposing to stop increasing emissions by 2030.
  • Very few of the INDC emissions will make real large cuts in emissions.
  • The aggregate forecast impact of all the INDC submissions, if fully enacted, will see global  emissions slightly higher than today in 2030, when according to the UNEP emissions GAP report 2017 for 1.5°C warming target they need to be 30% lower in just 12 years time. Paris Agreement Article 4.1 states something that is empirically incompatible with that aim.

In order to achieve the long-term temperature goal set out in Article 2, Parties aim to reach global peaking of greenhouse gas emissions as soon as possible, recognizing that peaking will take longer for developing country Parties,

  • The Paris Agreement allows “developing” countries to keep on increasing their emissions. With about two-thirds of global emissions (and over 80% of the global population), 30% emissions cuts may not be achieved even if all the developed countries cut emissions to zero in 12 years.
  • Nowhere does the Paris Agreement recognize the many countries who rely on fossil fuels for a large part of their national income, for instance in the Middle East and Russia. Cutting emissions to near zero by mid-century would impoverish them within a generation. Yet, with the developing countries also relying on cheap fossil fuels to promote high levels of economic growth for political stability and to meeting the expectations of their people (e.g. Pakistan, Indonesia, India, Turkey) most of the world can carry on for decades whilst some enlightened Governments in the West damage the economic futures of their countries for appearances sake. Activists trying to dictate Government policy through the Courts in a supposedly democratic country ain’t going to change their minds.

Plan B have responded to the judgement. I find this statement interesting.

Tim Crosland, Director of Plan B and former government lawyer, said: ‘We are surprised and disappointed by this ruling and will be lodging an appeal.

‘We consider it clear and widely accepted that the current carbon target is not compatible with the Paris Agreement. Neither the government nor the Committee on Climate Change suggested during our correspondence with them prior to the claim that the target was compatible.

Indeed, it was only in January of this year that the Committee published a report accepting that the Paris Agreement was ‘likely to require’ a more ambitious 2050 target

What I find interesting is that only point that a lawyer has for contradicting Mr Justice Supperstone’s statement that “Plan B Earth’s arguments were based on an “incorrect interpretation” of the Paris Agreement” is with reference to a report by the Committee on Climate Change. From the CCC website

The Committee on Climate Change (the CCC) is an independent, statutory body established under the Climate Change Act 2008.

Our purpose is to advise the UK Government and Devolved Administrations on emissions targets and report to Parliament on progress made in reducing greenhouse gas emissions and preparing for climate change.

The Committee is set up for partisan aims and, from its’s latest report, appears to be quite zealous in fulfilling those aims. Even as a secondary source (to a document which is easy to read) it should be tainted. But, I would suggest that to really understand the aims of the Paris Agreement you need to read the original and put it in the context of the global empirical and political realities. From my experience, the climate enlightened will keep on arguing for ever, and get pretty affronted when anyone tries to confront their blinkered perspectives.

Kevin Marshall

Why Plan B’s Climate Court Action should be dismissed

Summary

Taking court action to compel Governments to enforce the Paris Climate Agreement is against the real spirit of that Agreement. Controlling global GHG emissions consistent with 2°C, or 1.5°C is only an aspiration, made unachievable by allowing developing countries to decide for themselves when to start reducing their emissions. In the foreseeable future, the aggregate impact of emissions reduction policies will fail to even reduce global emissions. Therefore, costly emissions reductions policies will always end up being net harmful to the countries where they are imposed. Governments wanting to both be players on the world stage and serve their countries give the appearance of taking action of controlling emissions, whilst in substance doing very little. This is the real spirit of the Paris Climate Agreement. To take court action to compel a change of policy action in the name of that Agreement should be struck off on that basis. I use activist group Plan B’s case before the British Court to get the British Government to make even deeper emissions cuts than those under the Climate Change Act 2008.

Plan B’s Case at the High court

Last week BBC’s environment analyst Roger Harrabin reported Court action to save young from climate bill.

The campaigners – known collectively as Plan B – argue that if the UK postpones emissions cuts, the next generation will be left to pick up the bill.

It is seeking permission from a judge to launch formal legal action.

The government has promised to review its climate commitments.

A spokesperson said it was committed to tackling emissions.

But Plan B believes ministers may breach the law if they don’t cut emissions deeper – in line with an international agreement made in Paris at the end of 2015 to restrict global temperature rise to as close to 1.5C as possible.

From an obscure website crowdjustice

Plan B claim that the government is discriminating against the young by failing to cut emissions fast enough. During the hearing, they argued that the UK government’s current target of limiting global temperature rises to 2°C was not ambitious enough, and that the target ought to be lowered to 1.5°C, in line with the Paris Agreement that the UK ratified in 2015. Justice Supperstone postponed the decision until a later date.

Plan B on their own website state

Plan B is supporting the growing global movement of climate litigation, holding governments and corporations to account for climate harms, fighting for the future for all people, all animals and all life on earth.

What is the basis of discrimination?

The widely-accepted hypothesis is that unless global greenhouse gas (GHG) emissions are reduced to near zero in little more than a generation, global average temperature rise will rise more than 2°C above pre-industrial levels. A further hypothesis is that this in turn will cause catastrophic climate change. Consequent on both hypotheses being true gives the case for policy action. Therefore, failure to reduce global GHG emissions will imperil the young.

A further conjecture is that if all signatories to the Paris Agreement fulfil their commitments it is sufficient to prevent 1.5°C or 2°C of warming. There are a number of documents to consider.

First is the INDC submissions (i.e. Nation States communications of their intended nationally determined contributions), collected together at the UNFCCC website. Most are in English.  To find a country submission I suggest clicking on the relevant letter of the alphabet.

Second, to prevent my readers being send on a wild goose chase through small country submissions, some perspective is needed on relative magnitude of emissions. A clear secondary source (but only based on CO2 emissions) BP Data Analysis Global CO2 Emissions 1965-2017. More data on GHG emissions are from the EU Commissions EDGAR Emissions data and the World Resources Institute CAIT Climate Data Explorer.

Third is the empirical scale of the policy issue. The UNEP emissions Gap Report 2017 (pdf), published in October last year is the latest attempt to estimate the scale of the policy issue. The key is the diagram reproduced below.

The total of all commitments will still see aggregate emissions rising into the future. That is, the aggregate impact of all the nationally determined contributions is to see emissions rising well into the future. So the response it to somehow persuade Nations States to change their vague commitments to such an extent that aggregate emissions pathways sufficient to prevent 1.5°C or 2°C of warming?

The relevant way to do this ought to be through the Paris Agreement.

Fourth is the Adoption Paris Agreement itself, as held on the UNFCCC website (pdf).

 

Paris Agreement key points

I would draw readers to Article 2.1(a)

  • Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change;

Article 2.2

  • This Agreement will be implemented to reflect equity and the principle of common but differentiated responsibilities and respective capabilities, in the light of different national circumstances.

My interpretation is that the cumulative aggregate reduction will be only achieved by if those countries that (in the light of their national circumstances) fail to follow the aggregate pathways, are offset by other countries cutting their emissions by a greater amount. It is a numbers game. It is not just a case of compelling some countries to meet the 1.5°C pathway but to compel them to exceed it by some margin.

I would also draw readers to Article 4.1

In order to achieve the long-term temperature goal set out in Article 2, Parties aim to reach global peaking of greenhouse gas emissions as soon as possible, recognizing that peaking will take longer for developing country Parties, and to undertake rapid reductions thereafter in accordance with best available science, so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century, on the basis of equity, and in the context of sustainable development and efforts to eradicate poverty.

My reading is that any country defined as “developing” has only an aim of reducing emissions after peaking of their emissions. When they choose to do so depends on a number of criteria. There is not clear mechanism for deciding this, and no surrender of decision-making by countries to external bodies.

Implications of the Paris Agreement

Many developing countries emissions are increasing their emissions. They agreement does not compel them to change course in the near future. Empirically that means to achieve the goals the aggregate emission reductions of countries reducing their emissions must be such that they cancel out the emissions increases in the developing countries. Using EDGAR figures for GHG emissions, and the Rio Declaration 1992 for developing countries (called Non-Annex countries) I estimate they accounted for 64% of global GHG emissions in 2012, the latest year available.

 

All other sources sum to 19 GtCO2e, the same as the emissions gap between the unconditional INDC case and the 1.5°C case. This presents a stark picture. Even if emissions from all other sources are eliminated by 2030, AND the developing countries do not increase their emissions to 2030, cumulative global emissions are very likely to exceed the 1.5°C and the 2°C warming targets unless the developing countries reduce their emissions rapidly after 2030. That is close down fairly new fossil fuel power stations; remove from the road millions of cars, lorries and buses; and reduce the aspirations of the emerging middle classes to improving life styles. The reality is quite the opposite. No new policies are on the horizon that would significantly reduce global GHG emissions, either from the developed countries in the next couple of years, or the developing countries to start in just over a decade from now. Reading the comments in the INDC emissions (e.g. Indonesia, Pakistan, India), a major reason is that these governments are not willing to sacrifice the futures of their young through risking economic growth and political stability to cut their emissions. So rather than Plan B take the UK Government  to a UK Court, they should be persuading those Governments who do not share their views (most of them) of the greater importance of their case. After all, unlike proper pollution (such as smoke), it does not matter where the emissions are generated in relation to the people affected.

It gets worse. It could be argued that the countries that most affected by mitigation policies are not the poorest seeing economic growth and political stability smashed. It is the fossil fuel dependent countries. McGlade and Ekins 2015 (The geographical distribution of fossil fuels unused when limiting global warming to 2°C) estimated, said to achieve even 2°C target 75% of proven reserves and 100% of new discoveries must be left in the ground. Using these global estimates and the BP estimated proven reserves of fossil fuels I created the following apportionment by major countries.

 

The United States has the greatest proven fossil fuel reserves in terms of potential emissions. But if one looks at fossil fuel revenues relative to GDP, it is well down the league table. To achieve emission targets countries such like Russia, Saudi Arabia, Kuwait, Turkmenistan, Iraq, and Iran must all be persuaded to shut down their down sales of fossil fuels long before the reserves are exhausted, or markets from developing countries dry up. To do this in a generation would decimate their economies. However, given the increase in fossil fuel usage from developing countries, and the failure of developed countries to significantly reduce emissions through policy this hardly seems a large risk.

However, this misses the point. The spirit of the Paris Agreement is not to cut emissions, but to be seen to be doing something about climate change. For instance, China were held up by the likes of President Obama for aiming to both top out its emissions by 2030, and reduce emissions per unit of GDP. The USA and the EU did this decades ago, so China’s commitments are little more than a Business-as-usual scenario. Many other countries emissions reduction “targets” are attainable without much actual policy. For example, Brazil’s commitment is to “reduce greenhouse gas emissions by 43% below 2005 levels in 2030.” It sounds impressive, until one reads this comment under “Fairness and Ambition

Brazil’s current actions in the global effort against climate change represent one of the largest undertakings by any single country to date, having reduced its emissions by 41% (GWP-100; IPCC SAR) in 2012 in relation to 2005 levels.

Brazil intends to reduce emissions by a further 2% compared to 2005 levels. Very few targets are more than soft targets relative to current or projected trends. Yet the outcome of COP21 Paris enabled headlines throughout the world to proclaim a deal had been reached “to limit global warming to “well below” 2C, aiming for 1.5C”. It enables most Governments to juggle being key players on a world stage, have alarmists congratulating them on doing their bit on saving the planet, whilst making sure that serving the real needs of their countries is not greatly impeded. It is mostly win-win as long as countries do not really believe that targets are achievable. This is where Britain has failed. Under Tony Blair, when the fever of climate alarmism at its height, backed up by the political spin of New Labour and a Conservative opposition wanting to ditch its unelectable image, Green activists wrote the Climate Change Act 2008 with the strict targets to be passed. Britain swallowed climate alarmism whole, and now as a country that keep its promises is implementing useless and costly policies. But they have kept some form of moderation in policies until now. This is illustrated by a graphic from a Committee on Climate Change report last week “Reducing UK emissions 2018 – Progress Report to Parliament” (pdf) (and referenced at cliscep)

Whilst emissions have come down in the power sector they are flat in transport, industry and in buildings. Pushing real and deep reductions in these sectors means for young people pushing up the costs of motoring (placing driving a car out of the reach of many), of industry (raising costs relative to the countries – especially the non-policy developing countries) and buildings in a country where planning laws make home-owning unaffordable for many and where costs of renting is very high. This on top of further savings in the power industry will be ever more costly as the law of diminishing returns sets in. Forcing more urgent policy actions will increase the financial and other burdens on the young people of today, but do virtually nothing to reach the climate aspirations of the Paris Agreement due to Britain now having less than 1% of global emissions. The Government could be forced out of political fudging to impose policies that will be net harmful to the young and future generations.

Plan B are using an extreme activist interpretation. As reported in Climate Home News after the postponement.

“The UK is not doing enough,” Tim Crosland, director of Plan B told Climate Home News. “The benchmark target is now out of place. We are arguing that it is a breach of human rights.”

The UK has committed to cut emissions by at least 80% of 1990 levels by 2050, with an aim to limit global temperature rise to 2C.

Under the 2008 Climate Change Act, the secretary can revise the target to reflect significant developments in climate change science or in international law or policy.

Plan B want to see the target lowered to be in line with 1.5C, the lower target of the Paris Agreement, which the UK ratified in 2016.

As stated, insofar as the Paris Climate Agreement is a major development of policy, it is one of appearing to do a lot whilst doing very little. By these terms, the stronger case is for repealing the Act, not strengthening its clauses. 

But what if I am wrong on this Paris Agreement being just an exercise in appearances? This then it should be recognized that developing countries will only start to reduce their emissions at some time in the future. By implication, for the world to meet the 1.5°C warming limit, developing countries should be pursuing and emissions reduction pathway much steeper than the 25% reduction between 2015 and 2030 implied in the Emissions GAP Report graphic. It should be at least 50% and nearer 100% in the next decade. Given that the Climate Change Act was brought in so that Britain could lead the world on climate change, Plan B should be looking for a 100% reduction by the end of the year. 

Kevin Marshall

 

Hansen et al 1988 Global Warming Predictions 30 Years on

Last month marked the 30th anniversary of the James Hansen’s Congressional Testimony that kicked off the attempts to control greenhouse gas emissions. The testimony was clearly an attempt, by linking human greenhouse emissions to dangerous global warming, to influence public policy. Unlike previous attempts (such as by then Senator Al Gore), Hansen’s testimony was hugely successful. But do the scientific projections that underpinned the testimony hold up against the actual data? The key part of that testimony was a graph from the Hansen et al 1988* Global climate changes as forecast by Goddard Institute for Space Studies three-dimensional model, produced below.


Figure 1: Hansen et al 1988 – Figure 3(a) in the Congressional Testimony

Note the language of the title of the paper. This is a forecast of global average temperatures contingent upon certain assumptions. The ambiguous part is the assumptions.

The assumptions of Hansen et. al 1988

From the paper.

4. RADIATIVE FORCING IN SCENARIOS A, B AND C

4.1. Trace Gases

  We define three trace gas scenarios to provide an indication of how the predicted climate trend depends upon trace gas growth rates. Scenarios A assumes that growth rates of trace gas emissions typical of the 1970s and 1980s will continue indefinitely; the assumed annual growth averages about 1.5% of current emissions, so the net greenhouse forcing increase exponentially. Scenario B has decreasing trace gas growth rates, such that the annual increase of the greenhouse climate forcing remains approximately constant at the present level. Scenario C drastically reduces trace gas growth between 1990 and 2000 such that the greenhouse climate forcing ceases to increase after 2000.

Scenario A is easy to replicate. Each year increase emissions by 1.5% on the previous year. Scenario B assumes that growth emissions are growing, and policy takes time to be enacted. To bring emissions down to the current level (in 1987 or 1988), reduction is required. Scenario C one presumes are such that trace gas levels are not increasing. As trace gas levels were increasing in 1988 and (from Scenario B) continuing emissions at the 1988 level would continue to increase atmospheric levels the levels of emissions would have been considerably lower than in 1988 by the year 2000. They might be above zero, as small amounts of emissions may not have an appreciable impact on atmospheric levels.

The graph formed Fig. 3. of James Hansen’s testimony to Congress. The caption to the graph repeats the assumptions.

Scenario A assumes continued growth rates of trace gas emissions typical of the past 20 years, i.e., about 1.5% yr-1 emission growth; scenario B has emission rates approximately fixed at current rates; scenario C drastically reduces traces gas emissions between 1990 and 2000.

This repeats the assumptions. Scenario B fixes annual emissions at the levels of the late 1980s, whilst scenario C sees drastic emission reductions.

James Hansen in his speech gave a more succinct description.

We have considered cases ranging from business as usual, which is scenario A, to draconian emission cuts, scenario C, which would totally eliminate net trace gas growth by year 2000.

Note that the resultant warming from fixing emissions at the current rate (Scenario B) is much closer in warming impacts to Scenario A (emissions growth of +1.5% year-on-year) than Scenario C that stops global warming. Yet Scenario B results from global policy being successfully implemented to stop the rise in global emissions.

Which Scenario most closely fits the Actual Data?

To understand which scenario most closely fits the data, we need to look at that trace gas emissions data. There are a number of sources, which give slightly different results. One source, and that which ought to be the most authoritative, is the IPCC Fifth Assessment Report WG3 Summary for Policy Makers graphic SPM.1 is reproduced in Figure 2.

 Figure 2 : AR5 WG3 SPM.1 Total annual anthropogenic GHG emissions (GtCO2eq/yr) by groups of gases 1970-2010. FOLU is Forestry and Other Land Use.

Note that in Figure 2 the other greenhouse gases – F-Gases, N2O and CH4 – are expressed in CO2 equivalents. It is very easy to see which of the three scenarios fits. The historical data up until 1988 shows increasing emissions. After that data emissions have continued to increase. Indeed there is some acceleration, stated on the graph comparing 2000-2010 (+2.2%/yr) with 1970-2000 (+1.3%/yr) . In 2010 GHG emissions were not similar to those in the 1980s (about 35 GtCO2e) but much higher. By implication, Scenario C, which assumed draconian emissions cuts is the furthest away from the reality of what has happened. Before considering how closely Scenario A compares to temperature rise, the question is therefore how close actual emissions have increased compared to the +1.5%/yr in scenario A.

From my own rough calculations, total GHG emissions from 1990 to 2010 rose about 29% or 1.3% a year, compared to 41% or 1.7% a year in the period 1970 to 1990. Exponential growth of 1.3% is not far short of the 1.5%. The assumed 1.5% growth rates would have resulted in 2010 emissions of 51 GtCO2e instead of the 49 GtCO2e estimated, well within the margin of error. That is actual trends over 20 years were pretty much the business as usual scenario. The narrower CO2 emissions from fossil fuels and industrial sources from 1990 to 2010 rose about 42% or 1.8% a year, compared to 51% or 2.0% a year in the period 1970 to 1990, above the Scenario A.

The breakdown is shown in Figure 3.

Figure 3 : Rough calculations of exponential emissions growth rates from AR5 WG1 SPM Figure SPM.1 

These figures are somewhat out of date. The UNEP Emissions Gap Report 2017 (pdf) estimated GHG emissions in 2016 at 51.9 GtCO2e. This represents a slowdown in emissions growth in recent years.

Figure 4 shows are the actual decadal exponential growth trends in estimated GHG emissions (with a linear trend to the 51.9 GtCO2e of emissions in 2016 from the UNEP Emissions Gap Report 2017 (pdf)) to my interpretations of the scenario assumptions. That is, from 1990 in Scenario A for 1.5% annual growth in emissions; in Scenario B for emissions to reduce from 38 to 35 GtCO2e in(level of 1987) in the 1990s and continue indefinitely: in Scenario C to reduce to 8 GtCO2e in the 1990s.

Figure 4 : Hansen et al 1988 emissions scenarios, starting in 1990, compared to actual trends from UNIPCC and UNEP data. Scenario A – 1.5% pa emissions growth; Scenario B – Linear decline in emissions from 38 GtCO2e in 1990 to 35 GtCO2e in 2000, constant thereafter; Scenario C – Linear decline  in emissions from 38 GtCO2e in 1990 to 8 GtCO2e in 2000, constant thereafter. 

This overstates the differences between A and B, as it is the cumulative emissions that matter. From my calculations, although in Scenario B 2010 emissions are 68% of Scenario A, cumulative emissions for period 1991-2010 are 80% of Scenario A.

Looking at cumulative emissions is consistent with the claims from the various UN bodies, that limiting to global temperature rise to 1.5°C or 2.0°C of warming relative to some point is contingent of a certain volume of emissions not been exceeded. One of the most recent the key graphic from the UNEP Emissions Gap Report 2017.

Figure 5 : Figure ES.2 from the UNEP Emissions Gap Report 2017, showing the projected emissions gap in 2030 relative to 1.5°C or 2.0°C warming targets. 

Warming forecasts against “Actual” temperature variation

Hansen’s testimony was a clear case of political advocacy. By making Scenario B constant the authors are making a bold policy statement. That is, to stop catastrophic global warming (and thus prevent potentially catastrophic changes to climate systems) requires draconian reductions in emissions. Simply maintaining emissions at the levels of the mid-1980s will make little difference. That is due to the forcing being related to the cumulative quantity of emissions.

Given that the data is not in quite in line with scenario A, if the theory is correct, then I would expect:-

  1. Warming trend to be somewhere between Scenario A and Scenario B. Most people accept 4.2equilibrium climate sensitivity of the Hansen model was 4.2ºC for a doubling of CO2 was too high. The IPCC now uses 3ºC for ECS. More recent research has it much lower still. However, although the rate of the warming might be less, the pattern of warming over time should be similar.
  2. Average temperatures after 2010 to be significantly higher than in 1987.
  3. The rate of warming in the 1990s to be marginally lower than in the period 1970-1990, but still strongly positive.
  4. The rate of warming in the 2000s to be strongly positive marginally higher than in the 1990s.

From the model Scenario C, there seems to be about a five year lag in the model between changes in emission rates and changes in temperatures. However, looking at the actual temperature data there is quite a different warming pattern. Five years ago C3 Headlines had a post 2013: The NASA/Hansen Climate Model Prediction of Global Warming Vs. Climate Reality.  The main graphic is in Figure 6

Figure 6 : C3 Headlines – NASA Hansen Prediction Vs Reality

The first thing to note is that the Scenario Assumptions are incorrect. Not only are they labelled as CO2, not GHG emissions, but are all stated wrongly. Stating them correctly would show a greater contradiction between forecasts and reality. However, the Scenario data appears to be reproduced correctly, and the actual graph appears to be in line with a graphic produced last month by Gavin Schmidt last month in his defense of Hansen’s predictions.

The data contradicts the forecasts. Although average temperatures are clearly higher than in in 1987, they are not in line with the forecast of Scenario A which is closest to the actual emissions trends. The rise is way below 70% of the model implied by inputting the lower IPCC climate sensitivity, and allowing for GHG emissions being fractional below the 1.5% per annum of Scenario A. But the biggest problem is where the main divergence occurred. Rather than warming accelerating slightly in the 2000s (after a possible slowdown in the 1990s),  there was no slowdown in the 1990s, but it either collapsed to zero, or massively reduced, depending on the data set was used. This is in clear contradiction of the model. Unless there is an unambiguous and verifiable explanation (rather than a bunch of waffly and contradictory excuses ), the model should be deemed to be wrong. There could be natural and largely unknown natural factors or random data noise that could explain the discrepancy. But equally (and quite plausibly) those same factors could have contributed to the late twentieth century warming.

This simple comparison has an important implication for policy. As there is no clear evidence to link most of the observed warming to GHG emissions, by implication there is no clear support for the belief that reducing GHG emissions will constrain future warming. But reducing global GHG emissions is merely an aspiration. As the graphic in Figure 5 clearly demonstrates, over twenty months after the Paris Climate Agreement was signed there is still no prospect of aggregate GHG emissions falling through policy. Hansen et. al 1988 is therefore a double failure; both as a scientific forecast and a tool for policy advocacy in terms of reducing GHG emissions. If only the supporters would realize their failure, and the useless and costly climate policies could be dismantled.

Kevin Marshall

*Hansen, J., I. Fung, A. Lacis, D. Rind, S. Lebedeff, R. Ruedy, G. Russell, and P. Stone, 1988: Global climate changes as forecast by Goddard Institute for Space Studies three-dimensional model. J. Geophys. Res., 93, 9341-9364, doi:10.1029/JD093iD08p09341.