Fall in San Francisco: Jim Renwick’s AGU report

Jim RenwickI took part in the 2015 AGU Fall Meeting, held at the vast Moscone Center in San Francisco, 14-18 December. As always, it was an absolute cornucopia of everything to do with the Geo/Earth Sciences, from exoplanets to the earth’s core to climate change and science policy, delivered by over 20,000 geoscientists. The Fall Meeting is always a blast, a real mind-expander.

This year, I was committed to chairing sessions first thing on Monday morning and then again on Friday. Monday’s session was “Evaluating Reanalysis: What Can We Learn about Past Weather and Climate?” with my sub-session having a focus on polar regions. The Thu/Fri session was “Precipitation over Mountainous Terrain: Observations, Understanding, Modeling, and Future Prospects”. In between, I soaked up as much as I could, wandering the halls to hear and see fascinating presentations on climate history, science communication, sea ice, and designing climate change musicals for primary school children. Here’s a few highlights, my personal “tip of the iceberg” from this year’s meeting.
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The advice of fools: Newman and Kelly risible on rising seas

IssacCordalBerlinFormer ACT MP Muriel Newman — an extreme right-winger and no stranger to the wilder shores of climate denial — has waded into the debate about sea level rise and coastal hazards in Christchurch in a long-winded and unhelpful article at her NZ “Centre for Policy Research” web site. In many respects, her piece is par for the Hidebound course — full of misdirection, misrepresentation and schoolgirl errors of fact, motivated by a weird world view:

The reality is that unfortunately, carbon dioxide is being used as a political football. When radicals embraced the environmental movement in the seventies, driving out people like Dr Patrick Moore the founder of Greenpeace, they used the climate debate to conceal their real agenda – the global redistribution of wealth.

Newman takes as the text for her sermon a piece by Mike Kelly, a New Zealander who is a professor at the University of Cambridge in the UK. His offering is just as ill-informed as Newman’s — can it really be the case that a professor of technology, whose main expertise is in “advanced electronic devices for very high speed operation”, doesn’t understand the difference between weather forecasting and climate modelling? Perhaps Kelly should read a few introductory texts on climate modelling before pontificating so publicly — and so erroneously.

But what makes Newman and Kelly’s articles so unhelpful to coastal residents in Christchurch and elsewhere is not the parroting of climate denialist tropes, but the conclusion she reaches:

The Christchurch Council – and all other councils around New Zealand for that matter – should base their coastal hazard projections, on what has happened in the past. There is no perfect predictor of the future, but looking at what has actually happened in the past is better than seizing on unreliable models developed by those driving a political agenda.

Let’s do what Newman wants, and forget modelling future sea level rise. Let’s look at the past.

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Coal, climate change, and the New Zealand economy: winners, losers, and long-term users

Cross-posted from Coal Action Network Aotearoa

As the country reeled with the news last week that Solid Energy had gone into administration with a $300m debt, another event was happening in the Pacific that puts the debate in a context that it too seldom receives in New Zealand.

Sign on Kiribati's island of Tarawa. Photo: flickr
Sign on Kiribati’s island of Tarawa. Photo: flickr

On Thursday, Kiribati Prime Minister Anote Tong wrote to world leaders calling for a moratorium on new coalmines.

“Kiribati, as a nation faced with a very uncertain future, is calling for a global moratorium on new coal mines. lt would be one positive step towards our collective global action against climate change and it is my sincere hope that you and your people would add your positive support in this endeavour,” he wrote.

“The construction of each new coal mine undermines the spirit and intent of any agreement we may reach, particularly in the upcoming COP 21 in Paris, whilst stopping new coal mine constructions NOW will make any agreement reached in Paris truly historical.”

UK Economist Sir Nicholas Stern agreed: “The use of coal is simply bad economics, unless one refuses to count as a cost the damages and deaths now and in the future from air pollution and climate change,” he told Reuters (Stern’s full statement here).

In June, Pope Francis said in his encyclical that the use of “highly polluting fossil fuels needs to be progressively replaced without delay.”

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Postcards from La La Land: the Cnut conundrum

New Zealand’s merry little band of climate deniers are turning out to be a right bunch of Cnuts. Sea level rise and its implications for Christchurch and the wider world have been making news in recent weeks — as have new projections of rapid sea level rise over the remainder of this century. So what does a good climate denier do? To stay faithful to their core belief — that climate change isn’t happening, or isn’t going to be bad — they have to argue against policies designed to deal with its impacts, as well as those intended to cut carbon emissions. Sea level rise? Like Cnut, they line themselves up against the waves.

I’ve blogged many times on the challenge sea level rise poses for post-quake Christchurch. The 2011 quakes caused large parts of the city to drop by up to half a metre — effectively delivering decades of sea level rise in a matter of minutes. For some areas of the city tidal and run-off flooding are now commonplace.

The current debate on sea level issues has been prompted by the city council’s long term planning process — which recommends ((Based on a revised report (pdf) developed from consultants Tonkin & Taylor’s 2014 work.)) that development should be restricted in areas where future sea level rise is expected to cause problems. Not surprisingly, this has some owners of coastal properties concerned that they will lose out. The council has also looked at the idea of building a tidal barrier across the Avon-Heathcote estuary to protect the city.

Local politics and property owner self-interest is bumping into the harsh realities of climate change, leading to a wide variety of responses — including “it isn’t happening”.

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The encroaching sea: new NZ sea level rise maps

This guest post is by Jonathan Musther, who has just published an amazing series of highly detailed maps projecting future sea level rise scenarios onto the New Zealand coastline. If you live within cooee of the sea, you need to explore his maps. Below he explains why he embarked on the project.

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The effect of 10m sea level rise on Christchurch: say goodbye to St Albans, prepare to paddle in the CBD. Full map here.

For humans, sea-level rise will almost certainly be the most directly observable effect of climate change, and specifically of global warming. As the climate changes, many of the effects will be subtle, or if not subtle, they will at least be very complex. Summers may be warmer, or cooler; we may experience more rain at some times of year, and less at others; tropical storms may increase and they may be sustained further from the equator, but all of these changes are complex, and not necessarily obvious against the background complexity of any climate system. In contrast, there is something obvious and unstoppable about sea-level rise, there is no question that it will send anyone in its path running for the hills.

For some time I have been involved in searching for land appropriate for specific uses such as arable farming, water catchment, and off-grid living. When searching for land in this way, there are many, many criteria to consider, and of course one of these is potential future sea-level. Using GIS (Geographical Information System) software, and elevation models of the New Zealand landscape, it is possible to visualise sea-level rise, and select sites accordingly. Naturally, the next question is what sea-level rise to consider. It is possible to place an upper-limit on sea-level rise – after all, there’s only a finite amount of ice that could melt – but beyond that, we’re limited to informed guesswork.

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25m sea level rise: a sunken city and Banks Island. Full map here.

What is the maximum possible sea-level rise? It depends who you ask. Many sources place the maximum potential sea-level rise at around 60-64 metres, but these figures are rarely referenced, and don’t concur with the latest research. Other sources place the figure at around 80-81.5 metres, and while this appears to be well referenced and researched, it is based on work that is somewhat out of date. The best estimates I’ve been able to locate, based on recent measurements (and lots of them) are around 70 metres, but quite what the margin of error is remains uncertain. Of course, when considering future sea-level, we must remember that here in the South Pacific, we will likely experience increased numbers of more powerful tropical storms, with associated storm surges.

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At 80m, West Melton is a seaside township. Full map here.

The maps I created showing sea-level rise for the whole of New Zealand depict rises of 10, 25 and 80 metres. I have certainly received criticism for not focussing on more modest sea-level rises (e.g. 1 or 2 metres), but there are some good reasons for this: firstly, the resolution of the elevation models of New Zealand do not allow accurate predictions of such small rises. Secondly, larger sea-level rises pose a huge threat, and are therefore worth considering. I made a point of avoiding time frame predictions when producing the sea-level rise maps, partly because the time frame is largely irrelevant (if 80% of our homes are flooded, it’s bad news, no matter when) and partly because the range of expert estimates is huge. Study after study shows that we have underestimated ice-sheet instability, and it is almost universally accepted that large sea-level rise will be a consequence. Unfortunately, most studies place this sea-level rise at some unspecified time in the future – when, we’re not sure, but it’s far enough away that we needn’t worry…

So is a 10 or 25 metre sea-level rise likely? Unfortunately, the broad answer is yes. The Greenland, West and East Antarctic ice sheets are showing growing instability, and many researchers agree that they may have past a ‘point of no return’. Remember, the Greenland ice sheet alone, if completely melted, would lead to approximately a 7 m rise in global sea-level. Of course, we return to the issue of when this is likely to happen, and on that, the jury is out.

I firmly believe that to be good scientists, we must investigate the possibility of large sea-level rise, and its consequences. The time frame is unclear, the absolute rise is also unclear, but there really is something unstoppable about rising oceans. We are now well outside the sphere of collective human experience and expertise, and we should be very careful to prepare, as best we can, for a range of scenarios.