RTCC Respond Magazine 2014

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Climate marathon: IPCC nears finish line for seminal report

Last updated on 29 October 2014, 4:39 pm

Scientists will need to sift through over 200 comments, ranging from grammatical errors to strategic concerns
IPCC chair Rajendra Pachauri and IPCC WG-1 Co-Chair Thomas Stocker confer in Copenhagen (Photo by IISD/ENB)

IPCC chair Rajendra Pachauri and IPCC WG-1 Co-Chair Thomas Stocker confer in Copenhagen (Photo by IISD/ENB)

By Ed King

An exquisite form of torture is taking place this week in Copenhagen.

Over 500 delegates from 120 countries are working through a complex 100-page document that outlines the latest scientific understanding on climate change.

Officials are checking each page, line by line, and discussing whether the findings make sense.

Changes must be approved by consensus between government representatives and participating scientists. This is where politics and science collide.

The result of these endeavours will be the Intergovernmental Panel on Climate Change Synthesis Report, the final part of a mammoth six-year project.

It is likely to be one of the most carefully analysed documents this year and could determine economic and energy planning for next 20 years.

A final draft seen by RTCC says there is “unequivocal” evidence of change around the world, with potentially “irreversible” impacts if greenhouse emissions continue to rise.

But with three days of debate to go, the draft may yet change. A deluge of government reviews seen by RTCC offers a sense of priorities in capitals around the world.

Below is a taste of the variety of views from 181 pages of comments, which the IPCC is expected to address before Sunday. The comments have been copied directly, typos and all.

They reveal fears the dangers of climate change are not clear enough, that politicians will find the report too hard to read and a reassuring consensus that grammar is still important.

General feedback

The text has improved much from the earlier draft. However, the SPM still falls short of an actual synthesis and it does not provide a very good integration of the assessments of the three IPCC Working Groups. Rather, it still gives the impression of largely a copy-paste composite. [Government of Sweden]

The authors should take extra care to avoid complex and long sentences. In particular run-on sentences should be avoided. Preferably, long sentences should be broken up into shorter ones. [Government of Sweden]

This document should be prepared so as to be effective for the people who will only read the gray boxes. This report is a story, of what happens if we don’t act, and what can happen if we do… it should be an effective story. [Government of United States of America]

Clarity

This number tells very little. Is 0.1 much or little? [Government of Finland]

Does “unequivocal” mean “virtually certain”? If appropriate, defined uncertainty terminology should be used. [Government of United States of America]

SPM 1.3 This sentence is too generic and sounds obvious. Needs to be more explicit [Government of India]

What is the logical connection between the two sentences? [European Union] Headline 2.1

THE WHOLE SECTION IS MISLEADING. [WGIII 1.3, 5.3] [Government of Bolivia]

“unprecedented in at least 800,000 years”: Really? How certain? [Government of United States of America] Headline 1.2 SPM

This would be good to write out in terms of what the information means, in less scientific language. [Government of Sweden]

How long is “ever”? [Government of United States of America]

Does “clear” mean “virtually certain”? [Government of United States of America]

How is “unequivocal” defined? Is it “virtually certain”? [Government of United States of America]

What is meant by “consequential impacts”? [Government of United States of America]

What does “fractions of the global population” mean? Suggest considering whether there is a more clear way to state this. [Government of Canada]

Misestimate is not a real word. Underestimate or mistake would be more accurate in this context. [Government of Ireland] SPM 3.1

UK demands

[SPM 3.4] This is a key section with information very relevant to policy makers. Clear information on:

• The expected global temperature in 2100 without additional mitigation
• What emissions need to do to have a likely chance of reaching 2C and how this compared to current
• The scale of the challenge
• The risks of delay and the likely co-benefits

Should be provided and not hidden in supporting text and diagrams. The section is currently quite long and would better be split into two sections; the first on where we need to be to reach 2C and the second on where we currently are. The headline statements below could then reflect this new split [Government of United Kingdom of Great Britain & Northern Ireland]

SPM 4.5

One of the important co-benefits of climate change mitigation action, e.g. on emissions from the transport sector, is improved air quality. I would suggest making this explicit: “Co-benefits arise when investments in adaptation or mitigation can be managed to yield increased welfare from improved economic growth, public health, air quality or infrastructure.” [Government of United Kingdom of Great Britain & Northern Ireland]

Saudi concerns

Change ‘past 15 years’ to ‘past 17 years (1998-2014) [Government of Saudi Arabia] (RE warming pause)

Add from WGI SPM). It is very likely that the annual mean Antarctic sea ice extent increased at a rate in the range of 1.2 to 1.8% per decade (range of 0.13 to 0.20 million km2 per decade) between 1979 and 2012 [Government of Saudi Arabia]

There is low confidence in the scientific understanding of the small observed increase in Antarctic sea ice extent due to the incomplete and competing scientific explanations for the causes of change and low confidence in estimates of natural internal variability in that region. From WG1 SPM page 19 [Government of Saudi Arabia]

This figure is for the period 1951 to 2010. Warming was lower during the more recent period 1998 – 2010. This should be clearly indicated in this graph. [Government of Saudi Arabia]

Imponderables

“Plants cannot move”: this may seem odd unless there is a qualifier such as “naturally” or “by themselves”? Please check whether such an addition would be appropriate. [Government of Belgium] PM 2.3

SPM 2.3

We suggest the phrase “climate change is expected to lead to … greater likelihood of death …” needs to be reworded to more clearly explain what is meant. Everybody dies somtime, ie the unqualified likelhood of death is always 1.0. Perhaps what is meant is “climate change is expected to lead to … greater likelihood of EARLY death …? [Government of New Zealand]

Duplication

Editorial correction: The phrase “take account of” should occur only once in this sentence. [Government of New Zealand]

“take account of” is twice [Government of Finland]

“take account of” is repeated [Government of Italy]

Eliminate one of the two “take account of”. [Government of Switzerland]

typo: delete “take account of” as it is written twice. [Government of Ireland]

Referring to “of take account”: to delete. [European Union]

Delete repetition “take account of”. [Government of Russian Federation]

Editorial: delete “take account of” because these words have been repeated. [Government of Austria]

“take account of” is dublicated, one of them should be removed. [Government of Turkey]

Presentation

I have zoomed 150% in the pdf and have a huge monitor. The figure has a low resolution which makes it hard to read on paper. The sea level has rised so there is an erosion impact on western Europe soft coast which is not shown [Government of Denmark]

Table SPM.2: Please reconsider the use of colours in this table. [Government of Norway]
Read more on: IPCC
– See more at: http://www.rtcc.org/2014/10/29/climate-marathon-ipcc-nears-finish-line-for-seminal-report/#sthash.Z1X3nZRI.dpuf

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New research reveals what’s causing sea level to rise

Sea level rise is half due to melting ice and half due to ocean warming, including 13% from the deepest oceans, a new paper has found

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A fjord behind the town of Ilulissat in Greenland. Melting land ice accounts for about half the current rate of sea level rise, according to the latest research. Photograph: Reuters. A fjord behind the town of Ilulissat in Greenland. Melting land ice accounts for about half the current rate of sea level rise, according to the latest research. Photograph: Reuters.

There have been a number of studies recently on ocean warming and sea-level rise. Collectively, they are helping scientists unite around an emerging understanding of climate change and its impact on the Earth.

Most recently, a study by scientists Sarah Purkey, Gregory Johnson, and Don Chambers was published. This team was responsible for a 2010 paper that was groundbreaking in that it quantified very deep (abyssal) sea warming. This latest paper is, in some respects, a continuation of that work.

The researchers recognised that changes to sea levels are mainly caused by thermal expansion of ocean waters as they heat, changes to the saltiness of water, and an increase in ocean waters as ice melts and flows into the sea. The total annual sea level rise is about 3mm per year – the question is, how much of that is from expansion and how much is from melting?
Greg Johnson Greg Johnson

The researchers used a few tools to answer this question. One tool was ocean bottom pressure measurements. If you can measure changes to ocean pressure, you can deduce how much water is in the ocean. Another tool is through an inventory approach. This inventory method quantifies how much glaciers retreat, polar ice melts, and changes to water storage on land. The paper reports that both methods agree with each other. They conclude that increased water in the oceans is causing between 1.5–1.8 mm per year of sea level rise, depending, in part, on which years are under consideration.

The authors don’t just consider the ocean as a whole. They break the ocean regions into seven different sections because the change to ocean levels is not uniform. In some regions, waters are rising quickly, in others, the rise is much slower or zero. One reason for regional variability is that the Earth’s gravity is changing.

For instance, there is so much ice in Greenland and Antarctica that is melting and flowing into the ocean, the mass of these two regions is being reduced; therefore, the pull of gravity toward Greenland and Antarctica is changing. As a result, we expect water levels near Greenland and Antarctica may actually fall as those ice sheets melt.

But, ocean levels elsewhere, particularly UScoastlines, will rise more than average because of this same effect. I have a paper in press with Ted Scambos on this very topic that should be published in a few weeks.

Another reason sea level rise isn’t uniform is that there are local changes to heat and salt which can increase or decrease water density in certain regions, causing local changes to sea level. A third reason is that changes to wind patterns can slosh water around, causing it to build up in one area, fall in another.

In each of the seven ocean regions, the researchers collected temperature and salt measurements at carefully distributed sections. These measurements allowed them to calculate how much of the ocean rise is due to heat/salt effects. They compared the expected sea level rise to actual satellite measurements. The difference between expansion sea level rise and actual sea level rise is the contribution by melt water which flowed into the ocean. This method they call the residual measurement.

Then, they collected measurements from special satellites (GRACE) which measure local fluctuations in ocean mass. They compared the GRACE results with the residual measurement. It turns out they were in near perfect agreement; 1.5 mm per year of sea level rise is from added mass to the oceans. The rest is from expansion. Not only did the two methods agree, but they agreed region by region. They showed, for instance, that the South Atlantic and the South Indian/Atlantic Oceans are rising very rapidly. The North Pacific, South Pacific, and Indian Oceans are rising modestly. The southern Pacific is falling modestly and the North Atlantic is basically constant.

Next, they calculated the relative sea level rise for waters from the surface down to different depths (300, 1,000, 2,000, 3,000, 4,000, and 6,000 m) to determine which layers make the largest contributions to sea level rise. The authors report that the deeper we go into the ocean, the less heating has occurred (this is expected and well known). Interestingly, they find that every water layer, even the deepest waters, have contributed some to sea level rise. They also report that the sea level rise contribution from the layers 300-2,000 meters is much more than previously reported.

Dr Johnson summarised their results,

We find a small but measurable contribution from deep-sea warming to the global sea level budget (and hence global energy budget) from 1996–2006. The ocean warming is estimated directly from highly accurate, full-depth, oceanographic temperature data. The magnitude of the deep warming contribution to sea level below 2,000 m is about 13% of the total contribution of the mass trend below 2,000 m for that same time period.

I asked how this paper agrees or disagrees with a recent paper that reportedly showed the deepest ocean waters are not heating. He replied that the two studies actually agree with each other. They both show that the deepest ocean waters are likely contributing only a small fraction to the overall ocean energy/water rise. On the other hand, the uncertainty is largely because the deepest waters just don’t have a history of sufficient measurements to close the uncertainty range. He also stressed the importance of a proposed fleet of deep-water measuring devices (Deep Argo).

It is sometimes said that “global warming” is really “ocean warming”. Given the importance the oceans have on our past and future climate, you can be sure scientists around the world are working to better understand how much heat is going into the oceans, where the heat is going, and what will happen in the future. The recent publications are helping us close the uncertainty range and improve our knowledge. This is what progress looks like.