It was 1975 and, having spent more than a quarter of a century growing up, studying and working in Dunedin (at Otago Medical School), I noticed a feature in the Otago Daily Times under the headline "The next ice age cometh'', by a Reid Bryson. His view was that the planet was blocked from the sun not by clouds but by dust and was descending into the next ice age.
The shoddy analysis of observed temperatures of the time did not show unambiguous warming and he held the view that the earth might be heading for much more cooling. The temperature analysis used few climate stations and hardly any in the southern hemisphere.
University of Otago geography student Jill Gunn and I determined from temperature records that the wider New Zealand region was warming, and submitted our response, titled "Our weather is warming up'', to then ODT features editor Robin Charteris.
We uncovered that the climate in these maritime parts of the southern hemisphere had warmed up, temperature increases commencing in the late 1940s. This led us to publish a paper in the science journal Nature. In it we were critical of the wisdom of the time foreshadowing the descent into the next ice age: "... data for the southern hemisphere used so far have chiefly been obtained from locations between the equator and 40 degrees south,'' we wrote in volume 31 of Nature, in July 1975. "Information from higher latitudes, where any variations are amplified, is sparse. Here we present the results of an examination of a small area in the mid-latitudes of the southern hemisphere which has been warming over the past thirty years.''
To our surprise, the paper was featured in The Times, of London, as it challenged the wisdom of the time. So it was time for a career change, prompted by the ODT feature, by moving to Wellington to investigate, thoroughly, New Zealand's changing climate!
So the question is, after many "climate changes'' in the intervening 40 years, and taking into account the time the planet takes to warm up in response to increased greenhouse gases because of the thermal inertia (heat lag) of the oceans, where is the climate now, and where is it going?
Apart from one nation, all countries in the world have signed the Paris Agreement on climate change, committing to limit emissions of climate-warming greenhouse gases. The world's average temperature is at least 1degC warmer since observation records began in the 19th century, and New Zealand's average temperature 1.2degC warmer.
Over the past year, New Zealand has had an unprecedented marine and land heatwave covering an area of 4 million sq km, the size of the Indian subcontinent. In it both land and sea surface temperatures were the highest they have been since at least 1867, when land records in New Zealand started.
Swimmers and surfers also noted the unusual warmth of the waters around the South Island, a region normally not noted for its warm surf! Lifeguards noticed beaches were crowded much earlier in the season than usual. Snapper were caught for the first time in Fiordland. On land, in most wine-growing regions the hottest average grape flowering temperature in more than 20 years was recorded, which put the season several weeks ahead of normal. Hot temperatures in the South Island caused a massive melt-off, with a marked loss of permanent snow and ice in the Southern Alps.
And in the northern hemisphere, the extreme weather, linked to climate change, has been more serious still. The continental US had its hottest May on record, followed by the third-hottest June. Record-breaking heat has enveloped Europe and North Africa from the Sahara to above the Arctic Circle: Ouargla, in Algeria, setting a new African record with 51.3degC, Oslo over 30degC for 19 days, 31.9degC in northern Finland, 32.1degC in southern Finland, and a host of other records tumbling in Western Europe. New research from Oxford University's Environmental Changer Unit has concluded that the unprecedented temperatures seen over the northern summer of 2018 are a sign of things to come and a direct result of climate change. Closer to home, the worst drought ever is occurring in New South Wales.
And what of the immediate future? The United Kingdom Meteorological Office, once a year in January, issues a global mean temperature forecast for the coming few years.
The UK office determines that during the five-year period 2018-2022, global average temperature is expected to remain high and is very likely to be between 0.96degC and 1.54degC above the pre-industrial average period from 1850-1900. This compares with an anomaly of +1.14 plus or minus 0.1degC observed in 2016, currently the warmest year on record. And research recently published in Nature Communications has reinforced the UK Met Office predictions: "For 2018-2022, the probabilistic forecast indicates a warmer than normal period, with respect to the forced trend. This will temporarily reinforce the long-term global warming trend. The coming warm period is associated with an increased likelihood of intense to extreme temperatures.''
So warmer than normal temperatures and more heatwaves like we have seen can be expected in the next few years.
My climate journey described here has been one of academic discovery, traceable back to that article in the ODT on climate science in the 1970s, when climate warming in the wider New Zealand region was uncovered.
The United Nations Framework Convention on Climate Change (UNFCCC) in 1992, with the Kyoto Protocol, grew out of more and more robust science documenting, predicting and attributing global warming and its extremes to anthropogenic greenhouse gas emissions, which are now emerging pretty much on cue. The Paris Agreement, which is a rider on the legally binding UNFCCC, came into force because of the urgency of the issue.
Over the past 40 years we have twiddled our thumbs to the point where increasingly catastrophic climate-related weather events somewhere on the planet are now everyday news. To confine warming to 1.5degC, all greenhouse gas emissions must peak by 2020, with reductions by half of carbon dioxide by 2030 and of methane by 2040. The message from the latest IPCC report is humanity must start now, and agriculture cannot be excluded or delayed. Otherwise, if the global average temperature rises by 2degC above pre-industrial values, then about 400,000 of the species that we know could go extinct. Coral reefs would virtually all (greater than 99% ) be lost. This is one challenge we cannot afford to shirk. Success will not be possible without urgent commitment from every one of us on this odyssey in the Anthropocene.
Dunedin-born Jim Salinger is a visiting professor, a deputy editor of the journal Climatic Change and a lead author on two IPCC reports.