OPINION: As world leaders prepare to meet at a United Nations conference in Glasgow, Professor James Renwick, a prominent climate scientist and an author of the latest Intergovernmental Panel on Climate Change (IPCC) report, has written an open letter via the Herald to all New Zealanders calling for urgent action to save our planet. The letter has been signed by several colleagues, including fellow IPCC authors.
In a few weeks, the world's governments will meet in Glasgow to engage in negotiations around how to tackle climate change and reduce emissions of greenhouse gases. The globe is warming and the climate is changing because we are loading the air with more and more of these gases, especially carbon dioxide.
The Glasgow meeting is "COP26", the 26th step in negotiations that have been going on since the mid-1990s, but have not yet produced a reduction in emissions.
In fact, things have gotten a lot harder since COP got under way. In the roughly 30 years since the first COP meeting, the globe has emitted nearly half of all the carbon dioxide emitted in the past nearly 300 years, since coal was first burnt to power a steam engine. Emissions have gone up and up, despite short dips because of events like the Covid-19 pandemic and the Global Financial Crisis.
Over the same 30 years, the Intergovernmental Panel on Climate Change has been working, turning out a report on the state of the climate every few years. The first one came out in 1990 and the latest one, the Sixth Assessment, came out this year.
Since 1990, the climate science community has become much more certain about the effects of climate change, on the role humanity has in it, and the future dangers global society faces because of it. We now know that human activity (burning fossil fuels, mostly) is responsible for all the change in the climate over the last 70 years at least. We know climate change is affecting all parts of the globe and all aspects of the climate.
The changing climate affects everything. We all live in the climate system and we all owe our lives and our livelihoods to it. Changing the climate changes the rules about how and where we live our lives. As heatwaves and droughts make it harder to grow crops and feed ourselves, we will need to move our agricultural activity to chase the water and more bearable temperatures. As the seas rise and the coastlines move inland, we will have to move vast populations, cities, villages, and infrastructure on every coast.
The cost of climate change could become overwhelming this century, even for the wealthiest countries.
Under the Paris Agreement, the goal for all countries is to reduce emissions of greenhouse gases fast enough to limit global warming to somewhere between 1.5C and 2C, hopefully closer to the bottom end. The science community understands clearly that because carbon dioxide just builds up in the air, there is only so much we can emit before temperatures rise to 1.5C, or to any higher level.
Because we have spent so long doing nothing, time is now very short.
To stop global warming at 1.5C, we need to see global net emissions of carbon dioxide halve by 2030, just eight years away, and get to net zero no later than 2050. The New Zealand Government has advice from the Climate Change Commission on how to get this country on the necessary path, and that advice shows it is possible, and affordable, for Aotearoa at least. What is needed is for every country and every community to get to zero net emissions of carbon dioxide. As soon as possible.
No step is too small. Anything any of us can do to reduce our own carbon footprint is important. It could be choosing not to drive and taking public transport instead, using active transport (walking or cycling), buying second-hand clothes instead of new, reducing domestic waste, or eating low carbon (composting, growing your own veggies, adopting a more plant-based diet). For those who can afford it, action could include installing solar panels on your business, improving home insulation, or switching to an electric car or bike. There are more ideas on the Gen Less website.
The most important actions though are system-wide. Right now, it's hard to make low-carbon choices because our economy is set up around high carbon consumption. Governments can work with businesses to change that, bringing in policies that favour using more renewable power (more renewably-powered vehicles and public transport) or working with agriculture for a low emissions future. When the economy shifts to make the green choice the easy and cheap choice, then we'll really make progress.
One climate action that anyone can carry out is to lobby their MPs and government to let them know that we care about this issue and stand up and demand the most stringent and urgent action possible at COP.
Aotearoa, now is the time for action to be on the right side of history. We can all do this by making a shift in our thinking and moving into action.
• Dr Dan Hikuroa, Unesco Culture Commissioner
• Dr Sam Dean, IPCC contributing author
• Professor Bronwyn Hayward, IPCC AR6 author
• Professor Steven Ratuva, FRSNZ
• Professor Nick Golledge, IPCC AR6 author
• Professor Bruce Glavovic, IPCC AR6 author
• Associate Professor Anita Wreford, IPCC lead author
• Dr Olaf Morgenstern, IPCC AR6 author, NIWA
• Professor Dave Frame, IPCC AR6 author and Director of the NZ Climate Change Research Institute.
• Professor James Renwick, a member of the Intergovernmental Panel on Climate Change, is calling on all New Zealanders to push for greater action ahead of a United Nations conference in Glasgow.
Professor James Renwick is a leading climate scientist with four decades of experience in weather and climate research. He is a lead author and co-ordinating lead author on three assessment reports for the Intergovernmental Panel on Climate Change. He was awarded the 2018 Prime Minister's Prize for Science Communication.