Missing climate targets could cost trillions

If nations don’t meet their current goals for reducing greenhouse gas emissions, the global economy could lose around US$150-792 trillion in just one lifetime, according to a study published in the journal Nature Communications.

If, however, countries join forces in a global cooperation strategy to achieve the Paris Agreement targets of two or 1.5-degrees Celsius, the economic benefits of avoiding further climate-related damages could yield $127-$616 trillion by 2100. 

It would involve an upfront investment of around $16-103 trillion – less than one fifth of those savings – for the G20 economies, which for the US, for instance, would amount to $5.4-33.3 trillion.

With this “self-preservation strategy”, all countries would reap the rewards according to the authors, led by Yi-Ming Wei from the Beijing Institute of Technology, China, with a “significant positive cumulative net income before 2100”.

The analysis comes amid growing concerns that nations are making meagre progress in efforts to reach agreed emission reduction targets, requiring them to step up and catch up or pay a hefty price.

Already, the world is experiencing major repercussions from global warming, with extreme weather patterns impacting ecosystems, communities, infrastructure, human wellbeing and economies – and it will get much worse on current trajectories.

Addressing this increasingly urgent problem is clearly not a matter for one nation, says co-author Biying Yu. “It requires collective action and cooperation from countries around the world.”

But stepping up is daunting for nations worried about the short-term economic costs of investing in carbon-reduction technologies.

The researchers saw that showing countries the economic losses of not taking action versus the potential net gains might encourage them to reset their goals as a matter of self-preservation.

“Because climate change is a long-term global environmental externality and it may lead to a global catastrophe,” Yu says, “inaction to climate change may lead to substantial socio-economic losses, implying the occurrence of a broader cost than sufficient action.”

To explore this, the team developed China’s Climate Change Integrated Assessment Model (C3IAM) to simulate the self-preservation strategy for 134 nations in 12 regions of the world, incorporating rapid development of carbon capture and storage, renewable energy and negative emissions technologies.

Considering different scenarios, integrating information on each region’s social welfare, historical responsibility and economic capacity, the model weighed up costs and benefits to find the optimal, most equitable approach to mitigate global warming.

It provides precise emissions reductions goals, break-even points and ceiling costs, finding that higher contributions are needed from Japan, the US, Russia, China, India, Europe, Canada, Australia and New Zealand to meet both Paris Agreement targets.

“Implementing such a self-preservation strategy in a real world requires countries to recognise the gravity of global warming and to make breakthroughs in low-carbon technologies,” Yu says, highlighting the importance of supporting vulnerable countries.

“They may need capital and technology transfer from developed countries, which is consistent with Article 11 of the Paris Agreement.”