New Research

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Industrial-era global ocean heat uptake doubles in recent decades

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Formal detection and attribution studies have used observations and climate models to identify an anthropogenic warming signature in the upper (0–700 m) ocean1, 2, 3, 4. Recently, as a result of the so-called surface warming hiatus, there has been considerable interest in global ocean heat content (OHC) changes in the deeper ocean, including natural and anthropogenically forced changes identified in observational5, 6, 7, modelling8, 9 and data re-analysis10, 11 studies. Here, we examine OHC changes in the context of the Earth’s global energy budget since early in the industrial era (circa 1865–2015) for a range of depths. We rely on OHC change estimates from a diverse collection of measurement systems including data from the nineteenth-century Challenger expedition12, a multi-decadal record of ship-based in situ mostly upper-ocean measurements, the more recent near-global Argo floats profiling to intermediate (2,000 m) depths13, and full-depth repeated transoceanic sections5. We show that the multi-model mean constructed from the current generation of historically forced climate models is consistent with the OHC changes from this diverse collection of observational systems. Our model-based analysis suggests that nearly half of the industrial-era increases in global OHC have occurred in recent decades, with over a third of the accumulated heat occurring below 700 m and steadily rising.

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2915.html

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How Likely Is The Observed Recent Warmth?

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With the official numbers now in 2015 is, by a substantial margin, the new record-holder, the warmest year in recorded history for both the globe and the Northern Hemisphere. The title was sadly short-lived for previous record-holder 2014. And 2016 could be yet warmer if the current global warmth persists through the year.

One might well wonder: just how likely is it that we would be seeing these sort of streaks of record-breaking temperatures if not for human-caused warming of the planet?

Precisely that question was posed by several media organizations a year ago, in the wake of the then-record 2014 temperatures. Various press accounts reported odds anywhere from 1-in-27 million to 1-in-650 million that the observed run of global temperature records (9 of the 10 warmest years and 13 of the 15 warmest years each having had occurred since 2000) might have resulted from chance alone, i.e. without any assistance from human-caused global warming.

http://www.realclimate.org/index.php/archives/2016/01/how-likely-is-the-observed-recent-warmth/

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Dr Ricky Rood who IMO is always worth a read

Won't cha let me take you on a sea cruise? (It's about the hiatus.)

http://www.wunderground.com/blog/RickyRood/wont-cha-let-me-take-you-on-a-sea-cruise-its-about-the-hiatus

[knocker]

Human influence on climate in the 2014 southern England winter floods and their impacts

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A succession of storms reaching southern England in the winter of 2013/2014 caused severe floods and £451 million insured losses. In a large ensemble of climate model simulations, we find that, as well as increasing the amount of moisture the atmosphere can hold, anthropogenic warming caused a small but significant increase in the number of January days with westerly flow, both of which increased extreme precipitation. Hydrological modelling indicates this increased extreme 30-day-average Thames river flows, and slightly increased daily peak flows, consistent with the understanding of the catchment’s sensitivity to longer-duration precipitation and changes in the role of snowmelt. Consequently, flood risk mapping shows a small increase in properties in the Thames catchment potentially at risk of riverine flooding, with a substantial range of uncertainty, demonstrating the importance of explicit modelling of impacts and relatively subtle changes in weather-related risks when quantifying present-day effects of human influence on climate.

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2927.html

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In the Southern Ocean, a carbon-dioxide mystery comes clear

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Twenty thousand years ago, when humans were still nomadic hunters and gatherers, low concentrations of carbon dioxide in the atmosphere allowed the earth to fall into the grip of an ice age. But despite decades of research, the reasons why levels of the greenhouse gas were so low then have been difficult to piece together.

New research, published today in the leading journal Nature, shows that a big part of the answer lies at the bottom of the world. Sediment samples from the seafloor, more than 3 kilometers beneath the ocean surface near Antarctica, support a long-standing hypothesis that more carbon dioxide was dissolved in the deep Southern Ocean at times when levels in the atmosphere were low.

http://www.eurekalert.org/pub_releases/2016-02/teia-its020316.php

[knocker]

Eli musing this morning. Interesting little exchange in the comments.

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The key to understanding the greenhouse effect is that it is a problem of energy flows, not of energy per se. a zeroth order thermodynamical model in which there are two large (in thermo speak infinite) heat baths, the sun @ 6000 K and space at 3 K. The earth, stuck between these monsters is too small to be a heat bath is better though of as a heat engine, but a very lazy one producing no work on the external surroundings and therefore having to reject an equal amount of heat to space as it absorbs from the sun.

If the heat engine slows down because some thermal radiation is blocked by greenhouse gases, other parts of the spectrum have to heat up to compensate.

http://rabett.blogspot.co.uk/2016/02/temperature-baths.html

[Inga Horwood]

https://web.archive.org/web/20100707124649/http://www.globalcoral.org/LONG%20TERM%20ARCTIC%20ICE%20TRENDS%20AND%20GLOBAL%20WARMING.1.pdf

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Consequences of twenty-first-century policy for multi-millennial climate and sea-level change

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Most of the policy debate surrounding the actions needed to mitigate and adapt to anthropogenic climate change has been framed by observations of the past 150 years as well as climate and sea-level projections for the twenty-first century. The focus on this 250-year window, however, obscures some of the most profound problems associated with climate change. Here, we argue that the twentieth and twenty-first centuries, a period during which the overwhelming majority of human-caused carbon emissions are likely to occur, need to be placed into a long-term context that includes the past 20 millennia, when the last Ice Age ended and human civilization developed, and the next ten millennia, over which time the projected impacts of anthropogenic climate change will grow and persist. This long-term perspective illustrates that policy decisions made in the next few years to decades will have profound impacts on global climate, ecosystems and human societies — not just for this century, but for the next ten millennia and beyond.

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2923.html

Press release

Long-term picture offers little solace on climate change

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Climate change projections that look ahead one or two centuries show a rapid rise in temperature and sea level, but say little about the longer picture. A new looks at the next 10,000 years, and finds that the catastrophic impact of another three centuries of carbon pollution will persist millennia after the carbon dioxide releases cease.

http://www.sciencedaily.com/releases/2016/02/160208113009.htm

[knocker]

Marvel et al (2015) Part III: Response to Nic Lewis

http://www.realclimate.org/index.php/archives/2016/02/marvel-et-al-2015-part-iii-response-to-nic-lewis/

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A new study in Nature says the Earth, previously headed for an Ice Age before the Industrial Revolution, is likely to maintain its current warm phase in the glacial cycle for an unprecedented amount of time.

The researchers―Andrey Ganopolski, Ricarda Winkelmann, and Hans Joachim Schellnhuber of the Potsdam Institute for Climate Impact Research―first examined the effect of the Earth’s  orbital characteristics on the glacial cycle, but found that increased carbon dioxide (CO2) played a more important role.  Additionally, they found a critical relationship between CO2 and solar radiation that could aid in predicting the beginning of the next glacial period.

[knocker]

Sentinel-3: A new window on the changing state of our oceans

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Climate change is much discussed, says Dr Simon Keogh of the Met Office, and to inform the conversation the Met Office uses historical scientific data including sea-surface temperature records, based on data from the Along Track Scanning Radiometer (ATSR) series of satellite instruments. These instruments, designed and built in the UK, provided accurate infrared measurements of the Earth’s thermal emissions – including the heat signature emitted by the world’s oceans – until the untimely demise of ESA’s ENVISAT satellite in April 2012. Since the loss of ENVISAT, scientists have been eagerly awaiting ESA’s Sentinel-3 mission and hoping that it will provide high-precision data that will continue the ocean temperature record begun by ESA’s earlier satellites.

http://blog.metoffice.gov.uk/2016/02/16/sentinel-3-a-new-window-on-the-changing-state-of-our-oceans/

[Polar Maritime]

An interesting read here:

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New Research Shows Earth’s Tilt Influences Climate Change

12/14/15
BATON ROUGE – LSU paleoclimatologist Kristine DeLong contributed to an international research breakthrough that sheds new light on how the tilt of the Earth affects the world’s heaviest rainbelt. DeLong analyzed data from the past 282,000 years that shows, for the first time, a connection between the Earth’s tilt called obliquity that shifts every 41,000 years, and the movement of a low pressure band of clouds that is the Earth’s largest source of heat and moisture — the Intertropical Convergence Zone, or ITCZ.

“I took the data and put it through a mathematical prism so I could look at the patterns and that’s where we see the obliquity cycle, that 41,000-year cycle. From that, we can go in and look at how it compares to other records,” said DeLong, who is an associate professor in the LSU Department Geography & Anthropology.

With research collaborators at the University of Science and Technology of China and National Taiwan University, DeLong looked at sediment cores from off the coast of Papua New Guinea and stalagtite samples from ancient caves in China. DeLong’s data analysis revealed obliquity in both the paleontological record and computer model data. This research was published in Nature Communications on Nov. 25.

The standard assumptions about how the variations in the Earth’s orbit influences changes in climate are called Milankovitch cycles. According to these principles, the Earth’s tilt influenced ice sheet formation during the Ice Ages, the slow wobble that occurs on a 23,000-year cycle as the Earth rotates around the sun called precession affects the Tropics and the shape of the Earth’s orbit that occurs on a 100,000-year cycle controls how much energy the Earth receives.

“This study was interesting in that when we started doing the spectral analysis, the 41,000-year tilt cycle started showing up in the Tropics. That’s not supposed to be there. That’s not what the textbooks tell us,” DeLong said.

This finding shows that the tilt of the Earth plays a much larger part in ITCZ migration than previously thought, which will enable climate scientists to better predict extreme weather events. Historically, the collapse of the Mayan civilization and several Chinese dynasties have been linked to persistent droughts associated with the ITCZ. This new information is critical to understanding global climate and sustainable human socioeconomic development, the researchers said.

Additionally, climate scientists have begun to recognize that rather than shifting north and south, the ITCZ expands and contracts, based on this information.

Additional Link:

“Obliquity pacing of the western Pacific Intertropical Convergence Zone over the past 282,000 years,” Nature Communicationshttp://www.nature.com/ncomms/2015/151125/ncomms10018/full/ncomms10018.html

 

http://www.lsu.edu/mediacenter/news/2015/12/delong_ITCZ.as.php

[knocker]

New evidence confirms human activities drive global warming

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A new statistical technique, analysing data records since measuring started 150 years ago, independently confirms that man-made carbon dioxide (CO2) and methane (CH4) emissions have led to global warming, according to a JRC-led article published on 22 February 2016 in Nature Scientific Reports. The analysis also shows that the most pronounced consequences of such emissions are being felt in localised regions around the globe, such as Europe, North America, China, Siberia, the Sahel zone in Africa, and Alaska.

The authors investigated the causes of global warming using a new statistical method for quantifying causality to analyse the relation between time series data on greenhouse gas emissions and those on air temperatures in the last 150 years. The results confirm that recent global warming is mainly caused by increased anthropogenic (man-made) emissions and that further CO2 emissions to the atmosphere will lead to even stronger global warming.

https://ec.europa.eu/jrc/en/news/new-evidence-confirms-human-activities-drive-global-warming

[4wd]

2 hours ago, knocker said:

New evidence confirms human activities drive global warming

https://ec.europa.eu/jrc/en/news/new-evidence-confirms-human-activities-drive-global-warming

It seems very light on details of what they did differently to get the required result.
As soon as phrases like pumping CO2 into the atmosphere are used we know it's not an un-biased adventure in data manipulation.

The results confirm that recent global warming is mainly caused by increased anthropogenic (man-made) emissions and that further CO2 emissions to the atmosphere will lead to even stronger global warming.

This conclusion cannot be achieved through traditional, time-delayed correlations between temperature and GHG emissions changes or through ordinary least square regression analysis, as neither shows the causal relations.

[Methuselah]

2 minutes ago, 4wd said:

It seems very light on details of what they did differently to get the required result.
As soon as phrases like pumping CO2 into the atmosphere are used we know it's not an un-biased adventure in data manipulation.

 

So, what, pumping C0₂ into the atmosphere does nothing? The physics are pretty basic...

[4wd]

'Pumping CO2' into the atmosphere is clearly chosen to set the tone, it's like activists inserting  stock phrases such as pumping animals full of antibiotic or pumping crops full of pesticide.
Or pumping supporters of an agenda with propaganda phrases.

 

[Methuselah]

2 minutes ago, 4wd said:

'Pumping CO2' into the atmosphere is clearly chosen to set the tone, it's like activists inserting  stock phrases such as pumping animals full of antibiotic or pumping crops full of pesticide.
Or pumping supporters of an agenda with propaganda phrases.

 

It's also a fact!

[BornFromTheVoid]

Where did they say "pumping CO2"? The only similar line I see is "The analysis confirms this opposite trend for the last 150 years, when unprecedented amounts of CO2 started being pumped into the atmosphere in the industrial age."

I suppose when you've no substantive argument against something, you can always pick an innocuous phrase and declare that it's evidence of data manipulation. Eerily reminiscent of...

[knocker]

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Millennia of sea-level change

— stefan @ 22 February 2016

How has global sea level changed in the past millennia? And how will it change in this century and in the coming millennia? What part do humans play? Several new papers provide new insights.

2500 years of past sea level variations

This week, a paper will appear in the Proceedings of the National Academy of Sciences (PNAS) with the first global statistical analysis of numerous individual studies of the history of sea level over the last 2500 years (Kopp et al. 2016 – I am one of the authors). Such data on past sea level changes before the start of tide gauge measurements can be obtained from drill cores in coastal sediments. By now there are enough local data curves from different parts of the world to create a global sea level curve.

http://www.realclimate.org/index.php/archives/2016/02/millennia-of-sea-level-change/

Edited February 23, 2016 by knocker

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Some interesting research on the MJO and climate by Gina Henderson

 

[knocker]

NASA Finds Drought in Eastern Mediterranean Worst of Past 900 Years

A new NASA study finds that the recent drought that began in 1998 in the eastern Mediterranean Levant region, which comprises Cyprus, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey, is likely the worst drought of the past nine centuries.

https://www.nasa.gov/feature/goddard/2016/nasa-finds-drought-in-eastern-mediterranean-worst-of-past-900-years

[knocker]

Human influence on climate dates back to 1930s, new research finds

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WASHINGTON, DC — Humans have triggered the last 16 record-breaking hot years experienced on Earth (up to 2014), with our impact on the global climate going as far back as 1937, a new study finds.

The study suggests that without human-induced climate change, recent hot summers and years would not have occurred. The researchers also found that this effect has been masked until recently in many areas of the world by the wide use of industrial aerosols, which have a cooling effect on temperature

http://news.agu.org/press-release/human-influence-on-climate-dates-back-to-1930s-new-research-finds/

[knocker]

Science can now link climate change with some extreme weather events

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UNIVERSITY PARK, Pa. -- Extreme weather events like floods, heat waves and droughts can devastate communities and populations worldwide. Recent scientific advances have enabled researchers to confidently say that the increased intensity and frequency of some, but not all, of these extreme weather events is influenced by human-induced climate change, according to an international National Academies of Science, Engineering, and Medicine report released today (March 11).

http://www.eurekalert.org/pub_releases/2016-03/ps-scn031116.php

[knocker]

What drives uncertainties in adapting to sea-level rise?

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Let me get this off my chest – I sometimes get frustrated at climate scientists as they love to talk about uncertainties! To be sure, their work thrives on it. I’m someone who researches the projected impacts and adaptation to sea-level rise and gets passed ‘uncertain’ climate data projections to add to other ‘uncertain’ data projections in my impact modellers work bag. But climate scientists do a good job. Without exploring uncertainties, science loses robustness, but uncertainties in combination can become unbounded and unhelpful to end users.

Let’s take an adaptation to sea-level rise as an example: With increasing scientific knowledge, acceptance and mechanisms that would allow adaptation to potentially occur, one would think that adaptation would be straight forward to implement. Not so. Instead of hard and fast numbers, policy makers are faced with wide ranges of uncertainties from different sources, making decision making challenging. So what uncertainties are there in the drivers of change, and can understanding these uncertainties enable better decisions for adaptation?

http://www.realclimate.org/index.php/archives/2016/03/what-drives-uncertainties-in-adapting-to-sea-level-rise/