Farewell to 1.5°C: Facing the Reality of Climate Overshoot

Where We Are At

At the beginning of the year, politicians often give a “state of the nation” speech in which they offer their perspectives on what has gone before and what lies ahead. It is therefore perhaps appropriate that we dwell for a few moments on “where we are at” in the fight against environmental degradation and climate change as we enter 2023.

Climate Policy Is Way Off Target

Perhaps the most sobering thing to observe is that climate policy is way off target. The UN climate conference in Paris in 2015 enshrined the goal of limiting global warming to about 1.5°C. The intention was to coordinate national efforts to curb greenhouse gas emissions.

No-one remembered to inform the firing squad, however.

The same countries that piously signed the Paris agreement have not cut emissions enough to meet its targets; in fact global emissions are still growing. They adopted a Herculean goal without any plausible united plan for reaching it. It is not a goal the world is going to achieve.

1.2°C Hotter Already

The world is already about 1.2°C hotter than it was in pre-industrial times. Given the lasting impact of greenhouse gases already emitted, and the impossibility of stopping emissions overnight, there is no way Earth can now avoid a temperature rise of more than 1.5°C. There is still hope that the overshoot may not be too big, and may only be temporary, but even these consoling possibilities are becoming ever less likely.

2.8°C Under Current Policies

According to the UN Environment Programme:

• we will hit 2.8°C under current policies
• and 2.4°C if countries live up to all the commitments made in Paris and since

An emissions pathway with a 50/50 chance of meeting the 1.5°C goal was only just credible at the time of Paris. Seven intervening years of rising emissions mean such pathways are now firmly in the realm of the incredible.

For a 1.5°C Pathway, the Jig Is Up

To achieve it would require a huge new carbon-removal industry to be built more or less from scratch in just a couple of decades. It would require cuts in fossil fuel use which go beyond the extraordinary, with emissions reduced by over 40% by 2030. Even such extreme and implausible measures also count on negative emissions to then bring the temperature back down.

97 Hypothetical Scenarios

The huge assessment report the IPCC started publishing last year has 97 hypothetical scenarios in its “low-or-zero-overshoot” category. Only six have no overshoot. There remains no scenario in the IPCC assessment that peaks in 2025, and then reaches 1.5°C. Once one year reaches 1.5°C, the odds that the average over a couple of decades will soon rise to that level, and stay above it until after emissions fall to zero, are very high.

Serious Consequences

The consequences of the world’s failure to curb emissions are serious, and not just for coral atolls in the Pacific. Climate-related natural disasters are proliferating. Floods, heatwaves, hurricanes, fires and droughts are doing enormous economic damage, impeding transport, wrecking infrastructure, and sapping productivity.

Overshooting 1.5°C does not spell doom for the planet, but it is a death sentence for some people, ways of life, ecosystems, and even countries.

A Dose of Realism

Our response to all this should be a dose of realism. Many activists are reluctant to admit that 1.5°C is a lost cause. We should be chastened by failure, not lulled by false hope. We need to be pragmatic and face up to some harsh truths:

1. First, reducing emissions will require much more money.
2. Second, fossil fuels will not be abandoned overnight.
3. Third, since 1.5°C will be missed, greater efforts must be made to affordably adapt to and mitigate climate change.
4. Fourth, having accepted that the planet is going to grow dangerously hot, policymakers need to consider more radical ways to cool it.

Previously-Sidelined Ideas

Knowing that the 1.5°C milestone will fairly soon be in the rear-view mirror is leading people to take previously-sidelined ideas more seriously. The Climate Overshoot Commission (assembled under the auspices of the Paris Peace Forum) is looking at:

• greatly-enhanced adaptation
• carbon removal from the atmosphere
• and solar geoengineering

However, they are acutely aware of the risks involved. There is no obvious solution to the problem.

Every Fraction of a Degree Matters

The fundamental policy implication of the Paris agreement has not changed. The world needs to stabilise atmospheric greenhouse gas levels by massively reducing its emissions and by gaining the ability to reabsorb those emissions that it cannot abate.

Every fraction of a degree matters, and the less the temperature rises, the better.

Reality Must Now Trump Rhetoric

Reality must now trump rhetoric. If a new realism sees pressure for impossible levels of emission reduction give way for fierce advocacy for adaptation measures that are both plausible and vital, some at least would be well served. To let this moment pass without some hard thinking about how to set the world on a better trajectory would be to invite more disaster for both the human and non-human creation alike.

(facts mentioned in this article were gleaned from The Economist, November 5-11, 2022)