We are about to overshoot 1.5°C of planetary heating, according to a new United Nations report. We need to heed its warning, scientists say.

 

For the first time, a United Nations agency has reported unambiguously that we are about to cross 1.5°C of planetary heating, due to insufficient actions to reduce greenhouse gas emissions.

The UN Environment Programme (UNEP) report is a wake-up call, climate scientist Prof Andy Reisinger says. But not a reason to give up on the 1.5°C goal.

Our failure to reduce emissions comes with dangerous consequences in the form of heat-related deaths, flooding, failing harvests and economies, ice loss and bleaching coral reefs, he says.

‘‘These losses and damages will escalate further and often land hardest on the shoulders of those least responsible for those mounting risks.’’

But while we scale up efforts to deal with these disasters, we can’t give up on emission cuts — rather we need to accelerate efforts to reduce emissions of all greenhouse gases to keep at least some of the risks manageable.

‘‘We know how to and can still do this,’’ he says.

‘‘The report emphasises that the long-term goal remains to return to 1.5°C, as indeed governments reaffirmed only last year. Bringing global warming back down will be challenging and complex but is possible, provided that governments and industry begin to think and act beyond current net-zero targets.

‘‘As the report says, this is by no means an acceptable or preferred path to take, but is by now simply the best remaining option.’’

Dr Suli Vunibola, a senior lecturer at Lincoln University’s department of environmental management, says staying the right side of 1.5°C will mean Earth’s natural life-supporting systems remain on our side side, helping us down the emissions curve, rather than becoming our worst enemy when we cross the tipping point.

The root cause of our predicament is overproduction and consumption, he says.

‘‘A good case scenario would be, let’s collectively support necessary production, which will genuinely heal our natural systems and all humans’ well-being over the long term and avoid overshoot, and strictly omit unnecessary production globally.’’

It will be difficult, as our economic systems lean heavily on fossil-fuels and carbon-intensive industrial production, but business as usual is not the answer.

Earth Sciences New Zealand principal social scientist Dr Nicholas Cradock-Henry says the UNEP report is a reminder of Aotearoa’s exposure as a globally connected trading nation, vulnerable to international supply chain shocks, shifting marine ecosystems and geopolitical tensions.

We will need to account for the compounding and cascading impacts of changing hazards to safeguard our long-term agricultural productivity and interconnected infrastructure, he says.

‘‘We must act. We will not be unaffected. This will require a co-ordinated, all-of-society approach to respond immediately, acknowledge the true scale of the challenge, and mobilise a comprehensive response.’’

Public health physician and professor of environmental health at the University of Otago, Alex Macmillan, says that has not been the case of late.

The coalition government has weakened requirements to reduce emissions and responded inadequately on adaptation, she says.

‘‘Companies most responsible for climate change are successfully undermining life-saving action, while being protected from accountability by new legislation.

‘‘As doctors, we’ve seen this before with smoking. Change required exposing unethical and unlawful company tactics, restricting harmful advertising, and ending dangerous influence on policy. It’s time we did this for major climate polluters.’’

University of Canterbury professor of political science Bronwyn Hayward says the report highlights key challenges for the Pacific and anticipates a significant push to greater use of engineering techniques, including carbon capture and storage, but there is no guarantee, for example, that favoured net zero policies (particularly tree planting) will work in a world over 1.5°C of warming, where fires are a regular event.

‘‘We will also need global agreements to manage the unintended consequences of geoengineering to avoid some of the worst excesses of magical thinking, which could have wide ranging problems for food production and human health,’’ Prof Hayward says.

The report emphasises the power of social trust and inclusive decision making, she says.

‘‘Indigenous leadership, local community knowledge, and building social cohesion, by investing in health, housing and education are all vital to support a nation capable of taking concerted action to protect itself.’’ — Scimex