Tag: sea level

Getting it Wright on sea level rise

Sea level rise of up to 40cm around New Zealand by the middle of this century is already locked in and will cause significant problems for coastal communities and infrastructure, according to a new report just released by Dr Jan Wright, the Parliamentary Commissioner for the Environment. The report — Changing Climate and Rising Seas: Understanding the Science [pdf] — provides an overview of why sea levels are currently rising and why they are expected to continue rising over the rest of this century and beyond. A follow-up report due next year will “show in some detail which areas of the coastline around the country are most vulnerable to sea level rise and assess the risk to infrastructure in those areas”.

Introducing the report, Dr Wright said that the scientific evidence is now irrefutable. “The climate is changing and causing the sea to rise”.

“A rise of 30 cm may not sound much, but its impact will be very costly for many landowners. Damaging coastal floods will become increasingly frequent. The insurance industry is becoming aware of, and responding to, the increased flooding risk. Some councils and communities have already started to face hard questions.”

Commenting on the report for the Science Media Centre, Associate Professor Nancy Bertler of the Joint Antarctic Research Institute, Victoria University of Wellington/GNS Science, said:

The report provides an excellent summary on the current knowledge of past and future sea level rise including the main drivers and the regional patterns. Dr. Wright highlights the concern of the scientific community on the possibility of substantial and abrupt future contributions from the West Antarctic ice sheet.

Additional important considerations are that: worldwide over 200 million people live within one metre of sea level. The last time atmospheric carbon dioxide concentration was at 400 ppm (3-5 million years ago) the associated global temperatures caused the Greenland and West Antarctic ice sheets to catastrophically collapse – raising global sea level by around ten to twenty metres.

The rate at which sea level will rise has important implications on our ability to adapt. New research suggests that sea level could rise as quickly as 4 metres per 100 years (or 1 metre per 25 years). Assuming even a modest global sea level increase of 50 cm by 2100 (IPCC scenario RCP 4.5), the frequency of coastal inundation in New Zealand is predicted to increase by a multiplier of 1000 times.

Under such a scenario, an annual event becomes a daily event, a ‘100 year’ event occurs several times per year. As an approximation: every 0.1m rise triples the frequency of inundation events.

Dr Wright focusses on the near term implications for New Zealand, a sensible choice given the tendency to dismiss sea level rise as a problem for the distant future, but in my view she misses an opportunity to spell out the strong relationship between atmospheric CO2 levels and equilibrium sea level. The last time CO2 stood at 400 ppm, global sea level was about 20m higher than today. That’s where we’re heading, unless we can get greenhouse gas levels down, and it has very important implications for emissions policy. But I’m nit-picking…

Changing Climate and Rising Seas is a very readable introduction to the science of sea level rise, and gives a very clear picture of the state of current knowledge. It’s a welcome addition to what passes for national discourse on the inevitability of climate change and the necessity of adapting to what it brings. Next year’s report on regional impacts will be even more important.

NZ hikes terrorism threat to “low”, ignores Pentagon warning of “immediate” threat from climate change

A low threat of a terrorist attack? Never mind the climate. So, the threat of a terrorist attack on New Zealand is upon us has risen from “very low” to “low” — second to lowest in a ranking that has six levels. Cabinet is now urgently reviewing our security laws to make sure we’re equipped to deal with this horrific new threat. The media has dedicated hours of discussion, gigabytes of online content, and metres of newspaper articles to this important issue. I’m now quaking in my boots.

The day after John Key’s announcement of this new “low” threat, a major report on a global security threat went entirely unnoticed here in New Zealand. The Pentagon’s “2014 Climate Change Adaptation Roadmap,” released on October 14, warns that climate change is an “immediate threat” to national and global security, describing it as a “threat multiplier” that can worsen national security problems such as terrorism and the spread of infectious diseases.

The report says:

 “Rising global temperatures, changing precipitation patterns, climbing sea levels, and more extreme weather events will intensify the challenges of global instability, hunger, poverty, and conflict. They will likely lead to food and water shortages, pandemic disease, disputes over refugees and resources, and destruction by natural disasters in regions across the globe.”

Continue reading “NZ hikes terrorism threat to “low”, ignores Pentagon warning of “immediate” threat from climate change”

Oxfam: saving the tava’e (and the world)

This guest post is by Oxfam NZ‘s (relatively) new director, Rachael Le Mesurier. She’s off to the UN conference on Small Island Developing States in Apia next week, and here provides an interesting overview of the climate, sea level and other issues that are going to be on the agenda.

The national leaders of some of the world’s hottest island getaway spots are meeting in Apia, Samoa as the third UN conference on Small Island Developing States (SIDS) gets underway 1st – 4th September. 14 Pacific Island nations and Timor Leste, 16 Caribbean countries and eight small island nations from Africa, the Indian Ocean and the South China Sea are coming together, for the first time in the Pacific, under the theme “The sustainable development of Small Island Developing States through genuine and durable partnerships.”

But it isn’t all glorious sunsets and palm-tree lined white sand beaches in these small island nations. That perfect, tourist-brochure picture is already being impacted by climate change, economic isolation, social challenges and increasingly severe environmental disasters like earthquakes, tsunamis, volcanoes, cyclones and floods. The SIDS are coming together to alert the world that the Tava’e/Tropicbird — like the infamous canary in the coal mine — is struggling and the world needs to pay attention.

Continue reading “Oxfam: saving the tava’e (and the world)”

Friday melts, weird weather and whales (it’s been a long time…)

It’s been a long time since my last post: apologies for that. You may blame a bad cold, an urgent need for root canal work, the peak of the truffle season (and truffle tours for culinary heroes ((See also: why.)) ), the start of pruning and political distractions for the drop off in activity here. Normal service should resume in the near future, but meanwhile here are a few of the things that have caught my eye over the last week or two. You may therefore consider this an open thread – and given what follows, somewhat more open than usual…

The political distraction, of course, has been the response to Nicky Hager’s book, Dirty Politics. I haven’t yet read the book — it’s queued up on the iPad — but as everyone now knows, it concerns the sordid activities of right-wing attack blogger Cameron Slater, and in particular his close ties with senior government politicians. Slater has a long record of climate denial — often lifting material from µWatts or the Daily Mail to support his ignorant bluster — but the revelation that he published paid material for PR companies masquerading as his own opinion begs a question: was there a similar motivation for his climate denial posts?

Continue reading “Friday melts, weird weather and whales (it’s been a long time…)”

New Zealand’s Southern Alps have lost a third of their ice

This article by Jim Salinger, University of Auckland; Blair Fitzharris, University of Otago, and Trevor Chinn, National Institute of Water and Atmospheric Research, was first published at The Conversation. The photo at left shows the calving face of the Tasman Glacier in Dec 2013.

A third of the permanent snow and ice of New Zealand’s Southern Alps has now disappeared, according to our new research based on National Institute of Water and Atmospheric Research aerial surveys. Since 1977, the Southern Alps’ ice volume has shrunk by 18.4 km3 or 34%, and those ice losses have been accelerating rapidly in the past 15 years.

The story of the Southern Alps’s disappearing ice has been very dramatic – and when lined up with rapid glacier retreats in many parts of the world, raises serious questions about future sea level rise and coastal climate impacts.

The Southern Alps’ total ice volume (solid line) and annual gains or losses (bars) from 1976 to 2014 in km3 of water equivalent, as calculated from the end-of-summer-snowline monitoring programme. Continue reading “New Zealand’s Southern Alps have lost a third of their ice”