Tag: IPCC

IPCC WG3: it does not cost the world to save the planet

The IPCC has just released the summary for policymakers of the Working Group 3 report on mitigating climate change. It makes clear that the world has to act quickly to restrict carbon emissions to have a reasonable chance of restricting warming to 2ºC by the end of the century, but establishes that the costs of action are affordable.

A few key points:

  • Annual greenhouse gas emissions have risen 10 GtCO2eq between 2000 and 2010, and half of all emissions since 1750 have occurred in the last 40 years
  • If no further actions are taken to reduce emissions global mean surface temperature in 2100 will increase by 3.7 to 4.8°C compared to pre‐industrial levels
  • To have a reasonable chance of staying under 2ºC of warming in 2100 means restricting greenhouse gases to 450 ppm CO2eq
  • Hitting 450 ppm CO2eq will mean “substantial cuts in anthropogenic GHG emissions by mid‐century through large‐scale changes in energy systems and potentially land use”
  • Typical 450 ppm CO2eq scenarios include overshooting the target and then removal of CO2 by bionenergy with carbon capture and storage (BECCS), though “carbon dioxide removal (CDR) technologies and methods are uncertain and CDR technologies and methods are, to varying degrees, associated with challenges and risks”
  • The Cancun pledges are not consistent with cost-effective efforts to hit 2ºC, and are more likely to commit the world to 3ºC of warming
  • The sooner we act, the cheaper overall mitigation will be – as little as 0.06% of annual GDP growth to hit 450 ppm CO2eq

Commenting on the report for the Science Media Centre, VUW climate scientist Jim Renwick said:

The WGIII report charts many possible futures where we cap the warming at 2 degrees. Action, such as moving to 100% renewable electricity generation, needs to start immediately. New Zealand is as well-placed as any nation to lead the world on this, provided we have the political will. That appears to be lacking right now – there’s plenty of talk about emissions reductions targets, while at the same time we’re opening the country up to more oil drilling and coal mining. The latest MfE report shows New Zealand’s emissions have gone up 25% since 1990, and they are on track to keep rising.

Per head of population, we are some of the biggest emitters on the planet. Clean and green? 100% pure? Right now – I don’t think so.

Read more at The Guardian and BBC. I’ll have a post with more NZ reaction in due course.

Summary for policymakers (pdf)

Full report (available from April 15th)

TDB Today: Ragged right caught in reality’s shit sandwich

This week’s Daily Blog post takes a further look at NZ political responses to the release of the of the second part of the IPCC’s Fifth Report, and ponders how everyone who has gleefully claimed that adaptation is all we need to do will react when the third report — on mitigating carbon emissions — is released next week. Good risk management would mean planning to adapt to four degrees of warming, while aiming at emissions reductions that would restrict warming to two degrees…

IPCC WG2 impacts report released: fire, floods and rising seas in all our futures

After the usual run of late nights and argument, the IPCC has released the second part of its fifth report — the Working Group 2 report on climate impacts and risks management. Commenting on the report, VUW climate scientist Professor Tim Naish said “this latest report makes it quite clear that New Zealand is under-prepared and faces a significant ‘adaptation deficit’ in the context of the projected impacts and risks from global average warming of +2 to 4°C by the end of the century.”

The IPCC identifies eight key regional risks for New Zealand and Australia:

  • significant impacts on coral reefs in Australia as oceans warm and acidify
  • loss of montane ecosystems in Australia, as climate warms and snow lines rise
  • increased frequency of and intensity of flooding in NZ and Australia
  • water resources in Southern Australia will be under increased pressure
  • more intense heatwaves will bring increased death rates and infrastructure damage
  • increasing risks of damaging wildfires in New Zealand and southern Australia
  • increased risks to coastal infrastructure and ecosystems from sea level rise
  • risk of severe drying in parts of Australia could hit agricultural production

For New Zealand, extreme weather events such as flooding and heatwaves are expected to increase in frequency and severity, and rainfall is expected to increase on the already wet west coast and decrease in the east and north east. Sea level rise of up to one metre is expected to cause significant problems for coastal communities.

VUW’s Jim Renwick points to sea level rise as a big issue:

Every 10cm of rise triples the risk of a given inundation event, and we are expecting something like a metre of rise this century. That would mean today’s 1-in-100 year event occurs at least annually at many New Zealand coastal locations. New Zealand has a great deal of valuable property and infrastructure close to the coast that will be increasingly at risk as time goes on.

The Summary for Policymakers of the WG2 report is available here (pdf), and the final draft of the full report can be downloaded from this page. The Australia and New Zealand chapter (25) is here (pdf) and the Small Islands (Ch 29) here (pdf).

A huge amount of coverage of the report’s findings has already hit the net, and there will be more to come. Check out The Guardian‘s take on the five key points in the report, The Conversation’s examination of climate health risks, Graham Readfearn’s commentary on 25 years of IPCC warnings, and Peter Griffin’s look at the prospects for agriculture. I’ll have a post about the NZ political response to the report tomorrow.

AAAS “What We Know” Initiative: Same Denial, Different Issue – From Ozone Depletion to Climate Change

Dr Mario Molina (c) Centro Mario Molina
Dr Mario Molina
(c) Centro Mario Molina

(Cross-posted with permission from Polluterwatch.com)

It must be like Groundhog Day for Mario Molina, the scientist who has presided over the American Association for the Advancement of Science’s new report and publicity drive aimed at convincing Americans about the urgency of what’s happening on climate change.

The normally reticent AAAS has taken a highly unusual step. There’s no new science in it.  Instead, it summarises “what we know” on climate science, highlighting the 97% consensus on the issue and calling for action.

Why did they do it? The AAAS says it’s becoming alarmed at the American public’s views on climate change, stating in the opening paragraphs:

 “Surveys show that many Americans think climate change is still a topic of significant scientific disagreement.  Thus, it is important and increasingly urgent for the public to know there is now a high degree of agreement among climate scientists that human-caused climate change is real.” Continue reading “AAAS “What We Know” Initiative: Same Denial, Different Issue – From Ozone Depletion to Climate Change”

Saturday snark: a textbook for Vincent

As Stoat points out, the IPCC has released the reviewers comments on the Working Group One second order draft report. And as you might expect, the IPCC’s favourite inexpert commenter, the New Zealand Climate “Science” Coalition’s very own Vincent Gray was busy reviewing their work. Here’s comment 1-549 from Chapter One (pdf) by Gray:

The records shown are not “observations” and they are not “temperatures”. They are also not “globally averaged. They are a set of multiple averages, subtracted from an overall average, compiled from a vaying non-standardised set of maximum an minimum temperature measurements at varying weather sations and ship measurements. They were previously treated as “Mean Global Temperature anomaly” The uncertainties attached to each figure are very great, individual temperature measurements are rarely accurate to better than one degree, so a claimed “trend” over 100 years of less than one degree has a very low level of statistical significance. [Vincent Gray, New Zealand] (all spelling from IPCC doc)

The response from the editors is a minor classic of its kind:

Rejected – The comment does not reflect the scientific understanding. The errors in individual observations are not additive; we are also doing relative analysis that eliminates many of the concerns about individual errors. The reviewer obviously has a limited understanding of the associated error evaluation for analysis of large datasets. See Chapter 2 for more on the evaluation of these datasets. Or maybe even read a basic textbook. (my emphasis)

For more on accuracy versus precision, and the statistical power of large numbers, this classic post by Tamino is well worth a read.

There are other minor gems to be found as the reviewers deal with Monckton (in the “general” section) and John McLean (seemingly everywhere). In fact McLean’s ubiquity suggests that he may have acceded to Gray’s throne as the man with most comments on a single IPCC report. But don’t expect me to add them all up, I do have a life…