Climate change presents an existential threat - and a challenge that's going to require transformative action by governments and polluting industries across the globe. But what actions can we, as individuals take? In the first of a series of extracts from his contribution to the upcoming book, Climate Aotearoa: What's happening and what we can do about it, edited by former prime minister Helen Clark, Herald science reporter Jamie Morton offers some starting points. Read his suggestions and try our survey below to see what you can do to help.
New Zealand's climate change outlook is crammed with big, scary numbers.
By the middle of the century, when students who took part in last week's climate marches will be in their 40s, with children of their own, average temperatures will be, at best, 0.7C warmer than today.
That means more heatwaves, droughts and floods.
By the end of the century, assuming that greenhouse gas emissions continue to climb close to current levels, many parts of our country will record more than 80 days a year above 25C.
Most places typically only have between 20 and 40 days a year above that level now, yet already about 14 elderly people in Auckland and Christchurch die each year when the mercury climbs above only 20C.
If global temperatures climb just 1, 2 or 3C above current levels, that same death rate could rise to 28, 51 and 88 per year respectively.
The best-case scenario is that global warming stops somewhere between 2050 and 2070.
The worst case is that, by 2100, New Zealand temperatures end up more than 3C above present — and sea levels rise 1 metre or even higher.
Heavy rainfall and flooding events would quadruple, and extreme high temperatures could make many mid-latitude areas virtually unlivable in summer.
But perhaps the bleakest statistic of all is this one: 60 per cent.
That's the proportion of Kiwis, as indicated by a 2018 Ipsos poll commissioned by insurer IAG, who aren't sure whether humanity will do what's needed to avoid the worst of climate change.
Only one in 10 are optimistic that the world will act in time.
Another Ipsos poll suggests that just half of New Zealanders think that taking our own steps will alter the impact climate change ultimately has on us. Are they right?
What's your carbon footprint? Try this five-minute FutureFit survey, supported by Auckland Council, to find out.
As opponents to ambitious climate action like to remind us, New Zealand contributes just a tiny fraction — about 0.2 per cent — of the world's total greenhouse gas emissions.
Therefore we might say our climate change fate won't be dependent on us giving up red meat or buying an electric car, but on big-polluting nations like China, the US and India succeeding or failing to arrest their emissions curves before we blow through the all-crucial 2C mark.
It's also important to emphasise that most of the reductions we need must come from decarbonising our industries - and through compelling companies, governments and councils to commit to aggressive change.
But it's crucial that we all still do what we can, collectively, to avoid that wetter, warmer, wilder future of those grimmest projections.
Perhaps Kiwis get this, too: most of us want our government to be bold, even if the rest of the world doesn't seem to bother.
And there's much room for improvement.
On a per capita basis, New Zealand has an embarrassingly large carbon footprint, emitting some 18 tonnes of greenhouse gases per person each year.
By that measure, we're near the top 20 countries in the world — and within the top five in the OECD.
As climate campaigner Greta Thunberg puts it: you're never too small to make a difference.
So, where to start? Look no further than where you live — and shop.
Statistics New Zealand figures tell us that households are the largest contributor to New Zealand's carbon footprint — making up 71 per cent of it — because of the goods and services we consume.
That includes trips in the family cars, food and beverages, and the way we use power and water.
Still, the carbon footprint of an average Kiwi home is a tough one to calculate.
Who lives in a household and how much they spend, for instance, can explain nearly three-quarters of the variation that researchers have found in emissions.
One frequently referenced paper, by Wellington-based think-tank Motu Economic and Public Policy Research, points out food-related emissions account for roughly 40 per cent of what households produce, no matter their income.
Utilities like power make up nearly a third of emissions for poorer households, compared with just over 20 per cent for the wealthiest ones.
Yet richer homes still have a larger carbon footprint, partly because they consume more items such as meat and dairy, and they burn through much more petrol and diesel.
Fortunately, all of this points us towards some reasonably fast and easy gains we can make, starting right now.
If every Kiwi didn't drive one day a week, switched off their appliances at the wall, and converted to low-energy lightbulbs, New Zealand could save 386,500 tonnes of CO2-equivalent greenhouse gases per year — or around 5 per cent of our total emissions.
We can insulate our homes and install solar panels.
We can try having shorter showers, or outside the peak hours between 4pm and 8 pm, when there is the greatest demand on the grid for fossil-fuelled electricity generation.
Even a more efficient showerhead can make a difference: with one of these, a person who showers once a day can save the equivalent of burning a 20kg bag of coal in a year.
We can wash our clothes in cold water, make items such as clothes and home appliances last, buy second-hand, and repair rather than replace.
We can buy food that's sourced as locally as possible, buying New Zealand-grown rather than imported fruit, for example.
We can avoid products with too much packaging, and compost our kitchen scraps and garden waste. We might go a step further and grow what we eat.
We use gadgets like Fitbits to track our exercise. How can we do the same with emissions?
Researchers at Motu have put their knowledge into a handy calculator, called the Household Climate Action Tool.
There's also the nifty CoGo app, developed by Kiwi entrepreneur Ben Gleisner, which goes further by analysing household spending to calculate your real-time carbon footprint and encourage you to lower it.
In the UK, where CoGo been rolled out ahead of its planned arrival in New Zealand, users initially learnt that they were typically churning through 1000kg of CO2 equivalent each month.
That is roughly seven times higher than where Britain needs to be by 2030 to keep its emissions within goals to limit warming to 1.5C.
In other cases, we can make a difference by being more aware not only of what we're spending, but also whether we're spending on goods that are sustainably made.
That's not always straightforward.
According to Consumer New Zealand, only half of shoppers have trust in environmental product claims, while nearly three-quarters struggle to work out which products are actually greener.
There's a clear mandate for more clarity — and the New Zealand Sustainable Business Council reports that this matters to nearly nine in 10 consumers.
While Kiwis think electricity retailers and supermarkets are doing the most to reduce their footprint, they want brands in all industries to be more open and upfront about the steps they're taking — and actively communicate them.
Beyond shopping at outlets and websites that are based on eco-friendly principles — and there are now many to choose from — consumers can look out for product labels such the government-backed Environmental Choice tick, or AsureQuality or BioGro's organic certifications.
• This extract series continues tomorrow, as part of the Herald's Covering Climate Now coverage, with a look at red meat.
• Text extracted from Climate Aotearoa: What's happening and what we can do about it, a new book from a range of leading New Zealand climate scientists and commentators, edited by Helen Clark. Published by Allen & Unwin NZ. RRP$36.99. Available in stores from Monday, April 19