By Robert McLachlan 29/07/2020 3


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Is humanity doomed? If in 2030 we have not reduced emissions in a way that means we stay under say 2℃ (I’ve frankly given up on 1.5℃), are we doomed then?

Robert McLachlan, Massey University

Humanity is not doomed, not now or even in a worst-case scenario in 2030. But avoiding doom — either the end or widespread collapse of civilisation — is setting a pretty low bar. We can aim much higher than that without shying away from reality.

It’s right to focus on global warming of 1.5℃ and 2℃ in the first instance. The many manifestations of climate change — including heat waves, droughts, water stress, more intense storms, wildfires, mass extinction and warming oceans — all get progressively worse as the temperature rises.

Climate scientist Michael Mann uses the metaphor of walking into an increasingly dense minefield.

Good reasons not to give up just yet

The Intergovernmental Panel on Climate Change described the effects of a 1.5℃ increase in average temperatures in a special report last year. They are also nicely summarised in an article about why global temperatures matter, produced by NASA.

The global average temperature is currently about 1.2℃ higher than what it was at the time of the Industrial Revolution, some 250 years ago. We are already witnessing localised impacts, including the widespread coral bleaching on Australia’s Great Barrier Reef.

This graph shows different emission pathways and when the world is expected to reach global average temperatures of 1.5℃ or 2℃ above pre-industrial levels. Global Carbon Project, Author provided

Limiting warming to 1.5℃ requires cutting global emissions by 7.6% each year this decade. This does sound difficult, but there are reasons for optimism.

First, it’s possible technically and economically. For example, the use of wind and solar power has grown exponentially in the past decade, and their prices have plummeted to the point where they are now among the cheapest sources of electricity. Some areas, including energy storage and industrial processes such as steel and cement manufacture, still need further research and a drop in price (or higher carbon prices).

Second, it’s possible politically. Partly in response to the Paris Agreement, a growing number of countries have adopted stronger targets. Twenty countries and regions (including New Zealand and the European Union) are now targeting net zero emissions by 2050 or earlier.

A recent example of striking progress comes from Ireland – a country with a similar emissions profile to New Zealand. The incoming coalition’s “programme for government” includes emission cuts of 7% per year and a reduction by half by 2030.

Third, it’s possible socially. Since 2019, we have seen the massive growth of the School Strike 4 Climate movement and an increase in fossil fuel divestment. Several media organisations, including The Conversation, have made a commitment to evidence-based coverage of climate change and calls for a Green New Deal are coming from a range of political parties, especially in the US and Europe.

There is also a growing understanding that to ensure a safe future we need to consume less overall. If these trends continue, then I believe we can still stay below 1.5℃.

The pessimist perspective

Now suppose we don’t manage that. It’s 2030 and emissions have only fallen a little bit. We’re staring at 2℃ in the second half of the century.

At 2℃ of warming, we could expect to lose more than 90% of our coral reefs. Insects and plants would be at higher risk of extinction, and the number of dangerously hot days would increase rapidly.

The challenges would be exacerbated and we would have new issues to consider. First, under the “shifting baseline” phenomenon — essentially a failure to notice slow change and to value what is already lost — people might discount the damage already done. Continuously worsening conditions might become the new normal.

Second, climate impacts such as mass migration could lead to a rise of nationalism and make international cooperation harder. And third, we could begin to pass unpredictable “tipping points” in the Earth system. For example, warming of more than 2°C could set off widespread melting in Antarctica, which in turn would contribute to sea level rise.

But true doom-mongers tend to assume a worst-case scenario on virtually every area of uncertainty. It is important to remember that such scenarios are not very likely.

While bad, this 2030 scenario doesn’t add up to doom — and it certainly doesn’t change the need to move away from fossil fuels to low-carbon options.The Conversation

Robert McLachlan, Professor in Applied Mathematics, Massey University

This article is republished from The Conversation under a Creative Commons license. Read the original article.


3 Responses to “Are we doomed if we don’t manage to curb emissions by 2030?”

  • It is easy to write about cutting global emissions by 7.6% each year”it’s possible technically and economically” . Can you cite any evidence whatsoever to back up that assertion? I suppose the answer would rely most heavily on what is meant by ‘economically’. If by that you are suggesting that nearly all people are soon going to have to always work from home, travel nearly always by foot or by bike, have their leisure pursuits constrained to only those which use almost no energy (TV and internet), consume a lot less materially – then I might be able to believe it.
    Regarding the good intentions of the new Irish government, it should be obvious that intentions to not equate with achievements.
    As for your third point of optimism – we have had decades of awareness about the issue, and still anthropogenic global warming is practically unabated. A bit more outcry, or even a lot of such, is hardly likely to suddenly make the changes needed over the next decade.
    Then to forget about the issues posed by expecting poorer nations with large and relatively rapidly growing populations to limit their desired economic growth is to turn a very blind eye.
    To my knowledge nobody has any practical realistic suggestions as to how to significantly reduce the energy requirements for steel and cement manufacture. Just to say these “still need more research” is of no avail. Yes, if a sufficiently high carbon price is put on these everywhere then the output should drop, but this of course has an economic downside, especially for devloping nations.
    Sorry to be such a pessimist. Like everybody else I know, I’m not too keen on living out my remaining days as a hermit. I would think this also applies to the ‘School Strike 4 Climate’ folk on the whole.

  • Thanks Rod. On “technical and economical”, a 2019 review of 180 studies (Hansen et al., Energy 175 471-480) concluded that “The great majority of all publications highlights the technical feasibility and economic viability of 100% RE systems.” For example the studies by Jacobson at Stanford University are highly regarded. None that I have seen envisage the drastic lifestyle changes you’re considering. For example, on transport, many European cities have already achieved 1/3 mode share for each of active, public, and private transport and they are pretty happy with it. They are well placed to more than halve transport emissions in 10 years.

    Re: Ireland, I’m not sure if you’re arguing that all government plans and intentions are worthless, or just in the area of climate change. Either way, what would you suggest? At least Ireland is well into the fastest electricity transition yet seen anywhere in the world, so they must be doing something right. To me a bigger problem is plans that are designed to NEVER achieve what they claim. The NZ ETS and its successive weakening would be an example.

    Everything in my (albeit limited) understanding of history suggests that popular movements and public support are indeed very, very important ingredients of change. The fossil fuel companies’ strategies are a big reason for the insufficient action in the past 30 years and these were not known about until more recently.

    Here is a report on decarbonising industrial heat worldwide: https://www.icef-forum.org/roadmap/ and a blog post from the Environmental Defense Fund http://blogs.edf.org/markets/2020/07/10/why-decarbonizing-heavy-industry-is-difficult-but-also-possible/

  • Robert, thank you for your reply, and especially for the links. I really would love to believe that your optimism is justified, but as far as I can see progress has been and continues to be so dismally slow over the several decades since AGW has been widely recognised as a very serious threat (at least by educated people) that I can’t believe the world can get to averaging 7.6% emissions reductions over the next decade.
    Re your question to me about the Irish plans, I do not have any suggestions about how to ensure the required political ‘forcings’ there, or anywhere else. I did not mean to suggest that the Irish plans are worthless, but just that they are probably insufficient (by along shot?), and that plans do not always pan out in the end.