The Paris option of a 1.5C warming limit is ambitious beyond words, yet it’s looking more and more like the only sensible objective.
Eight months ago Australia supported a global effort to hold global warming to “well below 2C”, and to try to limit it to just 1.5C above pre-industrial levels.
We would do this, we agreed in Article 2 of the Paris Agreement, because “this would significantly reduce the risks and impacts of climate change”.
The agreement becomes legally-binding when 55 countries representing at least 55 per cent of global greenhouse emissions have ratified it. In Australia, that can be done by executive action.
In April, then-environment minister Greg Hunt said the government would “move immediately” to begin the ratification process and that Australia aimed to be “one of the countries to have achieved it this year”.
Other high-polluting countries including China and the US have said they will ratify this year. If that happens the treaty is all but certain to become law within 12 months. By contrast, the 1997 Kyoto Protocol took eight years to get the numbers after the US and Australia pulled out.
But the good news ends there. The Paris Agreement – the biggest, most far-reaching treaty ever – will ultimately have a profound impact on all national programs. It may be years before that impact is felt here, but when it happens Australians will wonder why we didn’t talk about it sooner.
For most of this year the government has been silent on our Paris obligations. There wasn’t a whisper of it in the May budget (while $1.3 billion was cut from renewable energy funding), or in the election campaign, or in treasurer Scott Morrison’s outline of his economic plan last week.
Eight months after Paris, all we know of government plans for climate action is “steady as she goes”. Yet without the help of some questionable land-use abatement we would not meet even our inadequate 2020 target, let alone the stronger (though still inadequate) 2030 goal.
Let alone pull our proper weight in the international community. Scientists and policy analysts preparing a 2018 report for the UN on pathways to a 1.5C limit are warning that the task, which will have to include pulling carbon dioxide out of the air, will be at best monumental, at worst utterly impossible.
They also warn that not trying is no option. Before 2020 governments will be called on to further strengthen their 2030 emission reduction targets. Australia can’t exclude itself from that exercise.
Multiple studies of temperature thresholds are saying that the Paris meeting was right to bring a 1.5C limit into the frame. Current science says that extreme heat, drought, storm and flood events will seriously threaten national economies well before the 2C threshold is crossed.
With surface temperatures already over 1C higher than in pre-industrial times, a study by the Zurich Institute for Atmospheric and Climate Science showed extreme heatwaves now happening about five times more often than they did in pre-industrial times.
The Zurich modelling found that 1.5C of warming would bring a further doubling of extreme heat events, and 2C would see another doubling. Similar exponential rises have been projected for sea levels and impacts on living systems. That extra half-degree matters a lot.
The world is already closing on 1.5C of warming. Records held by Britain’s Hadley Centre show the figure for March 2016 was 1.46C above the 1850-1900 average.
All 379 completed months since December 1984 have been warmer than their 20th century average, says the US National Oceanographic and Atmospheric Administration. The last of that string, July this year, was the warmest month ever recorded.
The most emphatic statistic in nearly three years of record-breaking warming has been NOAA’s monthly global surface temperature record. All 15 months from May 2015 to last July registered warmest-ever – the longest string of such extremes since records began 137 years ago.
The record monthly temperatures will soon come to an end, perhaps as soon as this month, because of the waning influence of the 2015-16 El Niño weather event in the tropical Pacific. But the drop-off will probably be too little, too late to stop 2016 entering the record-books as the warmest year.
University of Melbourne climate scientist David Karoly told Guardian Australia that in his estimate El Niño contributed about 0.2C to the July warming anomaly compared to a contribution from human greenhouse emissions more than five times that, over 1C.
Pinning down underlying causes of individual weather events is a trickier business. Earth has always delivered extreme and unusual weather, but numerous recent studies have found evidence that a warmer, more energetic atmosphere is making such events more frequent.
This year has produced a string of exceptional events. Tasmania’s wildfire rule-book went out the window with fires in its normally-wet northwest and central highlands. At the same time as the wilderness blaze, a deluge caused record-breaking flooding less than 100 km away.
The Great Barrier Reef was in headlines around the world in March and April with the revelation that exceptionally warm ocean waters had caused the permanent loss of about half the corals in the northern Reef. Bleaching events have happened before, but never on this scale, anywhere.
Early this northern summer Arctic sea ice disappeared at an unprecedented rate, with an area almost as big as Tasmania vanishing each week. By the end of July, sea-ice cover was about half what was considered normal 30 years ago. This year’s summer minimum is likely to be the second- or third-lowest on record.
A devastating firestorm in Canada’s northern pine forests happened in May, well before the start of the normal fire season, when more than 2,400 structures and nearly 600,000 hectares of forest were destroyed in and around the oil-sand city of Fort McMurray.
This year’s northern summer saw record-breaking heatwaves around the Persian Gulf, across southern Asia and Indonesia, and in the United States, with high night-time temperatures allowing no relief after scorching days. Smoke from widespread forest fires added to Indonesia’s discomfort.
In an echo of last summer’s Tasmanian experience, devastating wildfires in southern California happened at the same time as record-breaking flooding across southern Louisiana, prompting calls for a national state of emergency.
Floods, often unexpected, have killed hundreds and devastated communities in India, China, the US and Africa. From Brisbane to New Orleans to London to Shanghai, flood-prone cities and towns are having to rewrite their standing plans to deal with unprecedented water levels.
No single event can be ascribed to a warming planet, but together they carry the message that events that we might have expected once in a century are now recurring much more often. Climate science advises us to expect them eventually to happen multiple times in a year.
The Paris aspirational warming limit of 1.5C – already looking like the only sensible option – is a massive commitment that will test all countries. Australia has to face up to the fact – and soon – that its own targets are now grossly inadequate to the task at hand.
All the while the government stays mute, as if it thinks others will do our job for us, or the climate will somehow sort itself out. If only.
A WAY FORWARD: A Climate Action Hobart workshop next Sunday (starting 12.45 pm at Sustainable Living Tasmania, 71 Murray Street) will consider how communities and governments can be moved to stronger climate action. To register, email email@example.com