• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

RealClimate

Climate science from climate scientists...

  • Start here
  • Model-Observation Comparisons
  • Miscellaneous Climate Graphics
  • Surface temperature graphics
You are here: Home / Search for "rahmstorf"

Search Results for: rahmstorf

There was no pause

22 Jan 2017 by rasmus

I think that the idea of a pause in the global warming has been a red herring ever since it was suggested, and we have commented on this several times here on RC: On how data gaps in some regions (eg. the Arctic) may explain an underestimation of the recent warming. We have also explained how natural oscillations may give the impression of a faux pause. Now, when we know the the global mean temperature for 2016, it’s even more obvious.

Easterling and Wehner (2009) explained that it is not surprising to see some brief periods with an apparent decrease in a temperature record that increases in jumps and spurts, and Foster and Rahmstorf (2012) showed in a later paper how temperature data from the most important observations show consistent global warming trends when known short-term influences such as El Niño Southern oscillation (ENSO), volcanic aerosols and solar variability are accounted for.

A recent paper by Hausfather et al. (2017) adds little new to our understanding, although it confirms that there has not been a recent “hiatus” in the global warming. However, if there are doubts about a physical condition, then further scientific research is our best option for establishing the facts. This is exactly what this recent study did.

The latest findings confirm the results of Karl et al. 2015 from the National Oceanic Atmospheric Administration (NOAA), which Gavin described in a previous post here on RC. The NOAA analysis received unusual attention because of the harassment it drew from the chair of the US House Science Committee and the subpoena demand for emails.

[Read more…] about There was no pause

References

  1. D.R. Easterling, and M.F. Wehner, "Is the climate warming or cooling?", Geophysical Research Letters, vol. 36, 2009. http://dx.doi.org/10.1029/2009GL037810
  2. G. Foster, and S. Rahmstorf, "Global temperature evolution 1979–2010", Environmental Research Letters, vol. 6, pp. 044022, 2011. http://dx.doi.org/10.1088/1748-9326/6/4/044022
  3. Z. Hausfather, K. Cowtan, D.C. Clarke, P. Jacobs, M. Richardson, and R. Rohde, "Assessing recent warming using instrumentally homogeneous sea surface temperature records", Science Advances, vol. 3, 2017. http://dx.doi.org/10.1126/sciadv.1601207
  4. T.R. Karl, A. Arguez, B. Huang, J.H. Lawrimore, J.R. McMahon, M.J. Menne, T.C. Peterson, R.S. Vose, and H. Zhang, "Possible artifacts of data biases in the recent global surface warming hiatus", Science, vol. 348, pp. 1469-1472, 2015. http://dx.doi.org/10.1126/science.aaa5632

Filed Under: Climate Science, Instrumental Record, Oceans, RC Forum

Don’t make a choice that your children will regret

4 Nov 2016 by group

Dear US voters,

the world is holding its breath. The stakes are high in the upcoming US elections. At stake is a million times more than which email server one candidate used, or how another treated women. The future of humanity will be profoundly affected by your choice, for many generations to come.

The coming four years is the last term during which a US government still has the chance, jointly with the rest of the world, to do what is needed to stop global warming well below 2°C and closer to 1.5°C, as was unanimously decided by 195 nations in the Paris Agreement last December. The total amount of carbon dioxide the world can still emit in order to have at least a 50% chance to stop warming at 1.5 °C will, at the current rate of emissions, be all used up in under ten years! This time can only be stretched out by making emissions fall rapidly.

Even 2°C of global warming is very likely to spell the end of most coral reefs on Earth. 2°C would mean a largely ice-free Arctic ocean in summer, right up to the North Pole. Even 2°C of warming is likely to destabilize continental ice sheets and commit the world to many meters of sea-level rise, lasting for millennia. Further global warming will likely lead to increasing extreme weather, droughts, harvest failures, and the risk of armed conflict and mass migration.

greenland00037small

Meltwater on the Greenland Ice Sheet. Photo with kind permission by Ragnar Axelsson.

In case you have any doubts about the science: in the scientific community there is a long-standing consensus that humans are causing dangerous global warming, reflected in the clear statements of many scientific academies and societies from around the world. None of the 195 governments that signed the Paris Agreement saw any reasons for doubting the underlying scientific facts; doubts about the science that you see in some media are largely manufactured by interest groups trying to fool you.

You have a fateful choice to make. The policies of candidates and parties on climate change could hardly be more different. Hillary Clinton would continue to work with the international community to tackle the global warming crisis and help the transition to modern clean and renewable energies. Donald Trump denies that the problem even exists and has promised to go back to coal and to undo the Paris Agreement, which comes into force today, the 4th of November 2016, as culmination of over twenty years of negotiations.

Please consider this carefully. This is not an election about personalities, it is about policies that will determine our future for a long time to come. While the presidential race has gotten the most attention, voters should consider climate not just at the ‘top of the ticket’, but all the way down the ballot. Don’t make a choice that you, your children and your children’s children will regret forever.

David Archer, Rasmus Benestad, Ray Bradley, Michael Mann, Ray Pierrehumbert, Stefan Rahmstorf and Eric Steig

Filed Under: Climate Science, Communicating Climate

The answer is blowing in the wind: The warming went into the deep end

26 Apr 2013 by rasmus

There has been an unusual surge of interest in the climate sensitivity based on the last decade’s worth of temperature measurements, and a lengthy story in the Economist tries to argue that the climate sensitivity may be lower than previously estimated. I think its conclusion is somewhat misguided because it missed some important pieces of information (also see skepticalscience’s take on this story here).

The ocean heat content and the global mean sea level height have marched on.

While the Economist referred to some unpublished work, it missed a new paper by Balmaseda et al. (2013) which provides a more in-depth insight. Balmaseda et al suggest that the recent years may not have much effect on the climate sensitivity after all, and according to their analysis, it is the winds blowing over the oceans that may be responsible for the ‘slow-down’ presented in the Economist.

[Read more…] about The answer is blowing in the wind: The warming went into the deep end

References

  1. M.A. Balmaseda, K.E. Trenberth, and E. Källén, "Distinctive climate signals in reanalysis of global ocean heat content", Geophysical Research Letters, vol. 40, pp. 1754-1759, 2013. http://dx.doi.org/10.1002/grl.50382

Filed Under: Climate impacts, Climate modelling, Climate Science, El Nino, Greenhouse gases, In the News, Instrumental Record, Oceans

Model-data-comparison, Lesson 2

10 Apr 2008 by Stefan

In January, we presented Lesson 1 in model-data comparison: if you are comparing noisy data to a model trend, make sure you have enough data for them to show a statistically significant trend. This was in response to a graph by Roger Pielke Jr. presented in the New York Times Tierney Lab Blog that compared observations to IPCC projections over an 8-year period. We showed that this period is too short for a meaningful trend comparison.

This week, the story has taken a curious new twist. In a letter published in Nature Geoscience, Pielke presents such a comparison for a longer period, 1990-2007 (see Figure). Lesson 1 learned – 17 years is sufficient. In fact, the very first figure of last year’s IPCC report presents almost the same comparison (see second Figure).
[Read more…] about Model-data-comparison, Lesson 2

Filed Under: Climate Science

Atlantic circulation change summary

19 Jan 2006 by Gavin

Translations: (Français)

Nature this week has an excellent summary of the state of the science with regards to possible changes in the ocean thermohaline (or meridional) circulation in the Atlantic and its impact on climate. Even though it quotes a couple of us, it’s still worth reading if you want to understand how results like the Bryden et al paper – that suggested that the Atlantic overturning had reduced by 30% in recent decades – are assimilated into the scientific picture. [Read more…] about Atlantic circulation change summary

Filed Under: Climate Science, Oceans, Paleoclimate

Under and over the ice

10 Mar 2011 by Gavin

I really like the fact that there is still so much to discover about important parts of the climate system. The Bell et al paper in Science Express this week (final version in Science) reporting on the surprising results from airborne ground-penetrating radar studies of the Antarctic Ice Sheet is a great example. The ice sheets themselves are the biggest challenge for climate modelling since we don’t have direct evidence of the many of the key processes that occur at the ice sheet base (for obvious reasons), nor even of what the topography or conditions are at the base itself. And of course, the future fate of the ice sheets and how they will dynamically respond to climate warming is hugely important for projections of sea level rise and polar hydrology. The fact that ice sheets will respond to warming is not in doubt (note the 4-6 m sea level rise during the last interglacial), but the speed at which that might happen is highly uncertain, though the other story this week shows it is ongoing.

[Read more…] about Under and over the ice

Filed Under: Arctic and Antarctic, Climate Science

Our Books

1 Jan 2008 by group

This post is a list of books since 2005 (in reverse chronological order) that we have been involved in, accompanied by the publisher’s official description, and some comments of independent reviewers of the work. We will try and keep this list up to date as and when new books appear. We have also added links to the sidebar with the latest offerings.

Available now:

  • The Hockey Stick and the Climate Wars: Dispatches from the Front Lines, Michael Mann, Columbia University Press.
  • Global warming: Understanding the Forecast, Second Edition, David Archer, Wiley (2011).
  • Global Warming and Political Intimidation, by Raymond Bradley, University of Massachusetts Press (2011).
  • The Warming Papers: The Scientific Foundation for the Climate Change Forecast, by David Archer and Ray Pierrehumbert, Blackwell / Wiley (2010).
  • The Global Carbon Cycle: Princeton Primers in Climate, by David Archer, Princeton University Press (2010).
  • Principles of Planetary Climate by Ray Pierrehumbert. (Cambridge University Press, 2010)
  • The Climate Crisis: An Introductory Guide to Climate Change. David Archer and Stefan Rahmstorf, Cambridge University Press (2010). An unofficial guidebook to the IPCC Fourth Assessment Report.
  • Our Threatened Oceans Stefan Rahmstorf and K. Richardson (2008)
  • Climate Change: Picturing the Science. Gavin Schmidt and Joshua Wolfe, W.W. Norton (2009)
  • The Long Thaw: How Humans are Changing the Next 100,000 Years of Earth’s Climate. David Archer, Princeton University Press (2009)
  • Dire Predictions: Understanding Global Warming Michael Mann and Lee Kump, DK/Pearson (2008)
  • Wie bedroht sind die Ozeane? Stefan Rahmstorf and K. Richardson (2007, in German)
  • Global warming: Understanding the Forecast, David Archer (2006)
  • Der Klimawandel Diagnose, Prognose, Therapie, Stefan Rahmstorf and H. J. Schellnhuber (2006, in German, Korean, Vietnamese; Arabic version forthcoming)
  • Solar Activity and Earth’s Climate, Rasmus Benestad (2006, 2nd Edition)
  • Paleoclimatology: Reconstructing Climates of the Quaternary, Ray Bradley (2005, 2nd Edition)

Happy Reading!


The Hockey Stick and the Climate Wars: Dispatches from the Front Lines, Michael E. Mann (Columbia University Press).

Publisher’s description:

In its 2001 report on global climate, the Intergovernmental Panel on Climate Change of the United Nations prominently featured the “Hockey Stick,” a chart showing global temperature data over the past one thousand years. The Hockey Stick demonstrated that temperature had risen with the increase in industrialization and use of fossil fuels. The inescapable conclusion was that worldwide human activity since the industrial age had raised CO2 levels, trapping greenhouse gases in the atmosphere and warming the planet.

The Hockey Stick became a central icon in the “climate wars,” and well-funded science deniers immediately attacked the chart and the scientists responsible for it. Yet the controversy has had little to do with the depicted temperature rise and much more with the perceived threat the graph posed to those who oppose governmental regulation and other restraints to protect our environment and planet. Michael E. Mann, lead author of the original paper in which the Hockey Stick first appeared, shares the real story of the science and politics behind this controversy. He introduces key figures in the oil and energy industries, and the media front groups who do their bidding in sometimes slick, bare-knuckled ways to cast doubt on the science. Mann concludes with an account of the “Climategate” scandal, the 2009 hacking of climate scientists’ emails. Throughout, Mann reveals the role of science deniers, abetted by an uninformed media, in once again diverting attention away from one of the central scientific and policy issues of our time.


The Climate Crisis: An Introductory Guide to Climate Change. David Archer and Stefan Rahmstorf, Cambridge University Press, 2010.

Publisher’s description:

This book provides a concise and accessible overview of what we know about ongoing climate change and its impacts, and what we can do to confront the climate crisis. Highly illustrated in full colour, it lucidly presents information contained in the Intergovernmental Panel on Climate Change reports, making essential scientific information on this critical topic available to a broad audience.

David Archer and Stefan Rahmstorf – two outstanding scientists – bring us up-to-date on climate science in this remarkable and very readable book. This book deserves to be read by anyone interested in climate change.
–Paul Crutzen, Max Plank Institute for Chemistry, winner of the Nobel Prize for Chemistry for explaining the ozone hole

The key findings of the IPCC, written in plain and simple terms. Great value in informing the public at large about the science underlying the growing challenge of climate change.
-Rajendra Pachauri, Chairman of the IPCC and Director-General of The Energy Resources Institute

They are excellent communicators of the science to the general reader… One hopes for a wide readership for this measured book which clearly and thoughtfully sets out the results of the work of a great many scientists.
– Bryan Walker, Hot Topic, 19 January 2010


Climate Change: Picturing the science. Gavin Schmidt and Joshua Wolfe, W. W. Norton, April 2009

“Climate Change: Picturing the Science is a tour de force of public education. It is simply the best available collection of essays by climate scientists on the nature of human-induced climate change, the ways scientists have come to understand and measure the risks that it poses, and the options that we face….The editors, climatologist Gavin Schmidt and photographer Joshua Wolfe, have produced a collection of essays of uniformly outstanding quality, supported by photographs of beauty and insight.” 

-Jeffrey D. Sachs
Director, Earth Institute at
Columbia University

Publisher’s description:

An unprecedented union of scientific analysis and stunning photography illustrating the effects of climate change on the global ecosystem.

In this groundbreaking book, published by W.W. Norton & Company in April 2009 NASA climate scientist Gavin Schmidt and photographer Joshua Wolfe illustrate as never before the ramifications of shifting weather patterns for human society. Photographic spreads show us retreating glaciers, sinking villages in Alaska’s tundra, drying lakes. The text follows adventurous scientists through the ice caps at the poles to the coral reefs of the tropical seas. Marshalling data spanning centuries and continents, the book affirms the headlines with cutting-edge research and visual records, including contributions from experts on atmospheric science, oceanography, paleoclimatology, technology, politics, and the polar regions.

Reviews


The Long Thaw: How Humans are Changing the Next 100,000 Years of Earth’s Climate, David Archer (Princeton University Press, 2009).

Publisher’s description:

Global warming is usually represented as a hundred-year problem, say to the year 2100. In The Long Thaw, David Archer, one of the world’s leading climatologists, shows how a few centuries of fossil-fuel use will change the climate of the Earth dramatically for hundreds of thousands of years into the future. The great ice sheets in Antarctica and Greenland will take more than a century to melt, we think, but the climate impact from fossil fuel CO2 will last long enough for the ice sheets to respond fully to the warmer climate, changing sea level one hundred times more than the forecast for the year 2100. A planet-wide thaw driven by humans has already begun, but Archer argues that it is still not too late to avert dangerous climate change—if humans can find a way to cooperate as never before.

Reviews:

In this short book, David Archer gives us the latest on climate change research, and skillfully tells the climate story that he helped to discover: generations beyond our grandchildren’s grandchildren will inherit atmospheric changes and an altered climate as a result of our current decisions about fossil-fuel burning. Not only are massive climate changes coming if we humans continue on our current path, but many of these changes will last for millennia. To make predictions about the future, we rely on research into the deep past, and Archer is at the forefront of this field: paleoclimatology. This is the book for anyone who wishes to really understand what cutting-edge science tells us about the effects we are having, and will have, on our future climate.
Richard B. Alley, Penn State University

This is the best book about carbon dioxide and climate change that I have read. David Archer knows what he is talking about
James Hansen, NASA

Books on climate change tend to focus on what is expected to happen this century, which will certainly be large, but they often neglect the even larger changes expected to take place over many centuries. The Long Thaw looks at climate effects beyond the twenty-first century, and its focus on the long-term carbon cycle, rather than just climate change, is unique.
Jeffrey T. Kiehl, NCAR

A great book. What sets it apart is that it expands the discussion of the impacts of global warming beyond the next century and convincingly describes the effects that are projected for the next few thousand years. What also sets it apart is how deeply it takes general readers into the scientific issues of global warming by using straightforward explanations of often complex ideas.
Peter J. Fawcett, University of New Mexico

Archer has perfectly pitched answers to the most basic questions about global warming while providing a sound basis for understanding the complex issues frequently misrepresented by global warming skeptics. With a breezy, conversational style, he . . . provides a complete picture of climate change.
—Publishers Weekly

[An] enjoyable and fast-paced treatise. . . . Archer leads the reader to a simple yet accurate picture of climate changes, ranging from geological time scales to current warming, ice ages and prospects for the future.
—Susan Solomon, Nature


Dire Predictions: Understanding Global Warming Michael Mann and Lee Kump, (2008).

Publisher’s description:

The Intergovernmental Panel on Climate Change (IPCC) has been issuing the essential facts and figures on climate change for nearly two decades. But the hundreds of pages of scientific evidence quoted for accuracy by the media and scientists alike, remain inscrutable to the general public who may still question the validity of climate change.

Esteemed climate scientists Michael E. Mann and Lee R. Kump, have partnered with DK Publishing to present Dire Predictions–an important book in this time of global need. Dire Predictions presents the information documented by the IPCC in an illustrated, visually-stunning, and undeniably powerful way to the lay reader. The scientific findings that provide validity to the implications of climate change are presented in clear-cut graphic elements, striking images, and understandable analogies.

Readers will be able to understand the IPCC reports’ key concepts such as scientific uncertainty. They will also learn how to build a climate model and use it to predict future climates. Geoforensics is presented as a way to learn from the past by piecing together clues from prior climates.

Independent reviews:

Here’s a powerful, straight-forward guide to how scientists, economists, and engineers really understand the problem of global warming. It makes 20 years of research and consensus-building completely accessible to anyone who cares to know the truth–and to do something about it.
Bill McKibben, author of “The End of Nature”

With its eye-grabbing graphics and reader-friendly prose, “Dire Predictions” walks us through the findings of the world’s leading climate scientists – and places the ultimately responsibility for the human future directly at our feet.
Ross Gelbspan, author of “The Heat Is On” and “Boiling Point”

Dire Predictions is a must read for anyone who wants the straight facts on global warming. It cuts to the heart of the massive 2007 IPCC report, presenting major scientific findings in easy to understand language and graphics. Written by two of the scientific community’s most thoughtful researchers, Dire Predictions’ unbiased message about global warming arrives at a time when people need it most!
Dr. Heidi Cullen, Climate Expert at “The Weather Channel”



Wie bedroht sind die Ozeane?, Stefan Rahmstorf and K. Richardson, (Fischer 2007, in German, English version published 2008)

Publisher’s description:

Die Meere sind eine Grundlage unseres Lebens — sie regulieren unser Klima und sind ein wichtiger Nahrungslieferant. Doch wir zerstören sie durch globale Erwärmung, Überfischung und Verschmutzung. Das wird verheerende Folgen haben, wenn wir nicht rasch umdenken und handeln. Dieser Band zeigt Ansätze auf, wie wir unsere ozeanischen Ökosysteme wirkungsvoll schützen können.


Global warming: Understanding the Forecast, David Archer (Wiley-Blackwell, 2006).

Publisher’s description:

Global Warming: Understanding the Forecast is a comprehensive introduction to all aspects of global warming. Written in an accessible way, this important book examines the processes of climate change and climate stability, from the distant past to the distant future. Examining the greenhouse effect, the carbon cycle, and what the future may hold for global climate, this text draws from a wide range of disciplines, and not only summarizes scientific evidence, but also economic and policy issues, related to global warming. A companion website provides access to interactive computer models of the physics and chemistry behind the global warming forecast, which can be used to support suggested student projects included at the end of each chapter. Global Warming: Understanding the Forecast provides an essential introduction to this vital issue for both students and general readers, with or without a science background.

Independent reviews:

Rigorous but rewarding, David Archer’s book takes us through the science of global warming so that we can more effectively assess where the world may be heading.
Andrew S. Goudie, University of Oxford

David Archer’s book is an accessible, entertaining, but detailed account of how scientists are trying to predict future climate change. It is an excellent book and should be the first port of call for anyone wanting to delve deeper into exactly what goes into those global warming forecasts.
Mark Maslin, University College London, author of Global Warming: A Very Short Introduction

This is a wonderful book. Between the covers of a surprisingly slim paperback, David Archer has distilled nearly everything a concerned undergraduate student could wish to know about the workings of the climate system…overall, this book perfectly hits its target audience.
Keith Alverson, Intergovernmental Oceanographic Commission of UNESCO, Environmental Conservation


Solar Activity and Earth’s Climate, Rasmus Benestad, (Praxis-Springer, 2006, 2nd Edition, originally published 2002)

Publisher’s description:

The main purpose of this book is to introduce the reader to the subject of solar activity and the connection with Earth’s climate. It commences with a brief review of the historical progress on the understanding of the solar-terrestrial connection and moves on to an objective scrutiny of the various hypothesis. The text focuses on how knowledge about the solar cycle and Earth’s climate is obtained. It includes discussion of observations, methods and the physics involved, with the necessary statistics and analysis also provided, including an examination of empirical relations between sunspots and the Earth’s climate. The author reviews plausible physical mechanisms involved in any links between the solar cycle and the Earth’s climate, emphasizing the use of established scientific methods for testing hypothesized relationships.


Der Klimawandel Diagnose, Prognose, Therapie, S. Rahmstorf and H. J. Schellnhuber (2006) (in German, Korean, Vietnamese; Arabic version forthcoming)

Independent reviews:

“In dem Buch “Klimawandel” in der Reihe “Wissen” des C.H. Beck Verlages melden sich zwei ausgewiesene Fachleute zu Wort: Hans-Joachim Schellnhuber ist Gründer und Direktor des Potsdam-Instituts für Klimafolgenforschung und Professor für Theoretische Physik an der Universität Potsdam. Stefan Rahmstorf forscht am Potsdam-Institut für Klimafolgenforschung und ist Professor für Physik der Ozeane an der Universität Potsdam. Auf 144 Seiten geht es einmal quer durch das Fachgebiet, das die Autoren in fünf Abschnitte aufgeteilt haben: Die Klimageschichte der Erde; die derzeitige globale Erwärmung und ihre Ursachen, die Folgen des Klimawandels; die öffentliche Diskussion um den Klimawandel und schließlich die möglichen Lösungswege. Viele ihrer Aussagen und Analysen zum Klimawandel sind bekannt – doch man hat sie selten so kompakt, übersichtlich und kompetent auf so wenig Raum zusammengefasst gefunden.”
Susanne Billig, Deutschlandradio Kultur, 23. März 2006

“Stefan Rahmstorf und Hans-Joachim Schellnhuber haben ein Buch geschrieben, das einen hervorragenden Überblick über Erforschung, Folgen und Lösungsmöglichkeiten des Klimaproblems gibt.”
RBB-Inforadio, 8. April 2006


Paleoclimatology: Reconstructing Climates of the Quaternary, Ray Bradley, (Academic Press, 2nd edition, 2005, originally published in 1999).

Publisher’s description:

Raymond S. Bradley provides his readers with a comprehensive and up-to-date review of all of the important methods used in paleoclimatic reconstruction, dating and paleoclimate modeling. Two comprehensive chapters on dating methods provide the foundation for all paleoclimatic studies and are followed by up-to-date coverage of ice core research, continental geological and biological records, pollen analysis, radiocarbon dating, tree rings and historical records. New methods using alkenones in marine sediments and coral studies are also described. Paleoclimatology, Second Edition, is an essential textbook for advanced undergraduate and postgraduate students studying climatology, paleoclimatology and paleoceanography worldwide, as well as a valuable reference for lecturers and researchers, appealing to archaeologists and scientists interested in environmental change.

Independent Reviews:

Paleoclimatology is a definite “must-have” for anyone working in climate studies and highly recommended for anyone seriously interested in our climate.
William R. Green, The Leading Edge

This thorough, well referenced text will prove to be indispensable to anyone involved in the study of past and current climate change and modeling.
Southeastern Naturalist


Filed Under: Climate Science, Communicating Climate

2012 Updates to model-observation comparisons

7 Feb 2013 by Gavin

Time for the 2012 updates!

As has become a habit (2009, 2010, 2011), here is a brief overview and update of some of the most discussed model/observation comparisons, updated to include 2012. I include comparisons of surface temperatures, sea ice and ocean heat content to the CMIP3 and Hansen et al (1988) simulations.
[Read more…] about 2012 Updates to model-observation comparisons

Filed Under: Aerosols, Arctic and Antarctic, Climate modelling, Climate Science, El Nino, Greenhouse gases, Instrumental Record, Model-Obs Comparisons

Sea-level rise: Where we stand at the start of 2013

9 Jan 2013 by Stefan

Progress has been made in recent years in understanding the observed past sea-level rise. As a result, process-based projections of future sea-level rise have become dramatically higher and are now closer to semi-empirical projections. However, process-based models still underestimate past sea-level rise, and they still project a smaller rise than semi-empirical models.

Sea-level projections were probably the most controversial aspect of the 4th IPCC report, published in 2007. As an author of the paleoclimate chapter, I was involved in some of the sea-level discussions during preparation of the report, but I was not part of the writing team for the projections. At the core of the controversy were the IPCC-projections which are based on process models (i.e. models that aim to simulate individual processes like thermal expansion or glacier melt). Many scientists felt that these models were not mature and understated the sea-level rise to be expected in future, and the IPCC report itself documented the fact that the models seriously underestimated past sea-level rise. (See our in-depth discussion published after the 4th IPCC report appeared.) That was confirmed again with the most recent data in Rahmstorf et al. 2012.
[Read more…] about Sea-level rise: Where we stand at the start of 2013

References

  1. S. Rahmstorf, G. Foster, and A. Cazenave, "Comparing climate projections to observations up to 2011", Environmental Research Letters, vol. 7, pp. 044035, 2012. http://dx.doi.org/10.1088/1748-9326/7/4/044035

Filed Under: Climate Science, Instrumental Record, IPCC, Oceans

The global temperature jigsaw

17 Dec 2013 by Stefan

Since 1998 the global temperature has risen more slowly than before. Given the many explanations for colder temperatures discussed in the media and scientific literature (La Niña, heat uptake of the oceans, arctic data gap, etc.) one could jokingly ask why no new ice age is here yet. This fails to recognize, however, that the various ingredients are small and not simply additive. Here is a small overview and attempt to explain how the different pieces of the puzzle fit together.

AR5_temp_obs

Figure 1 The global near-surface temperatures (annual values at the top, decadal means at the bottom) in the three standard data sets HadCRUT4 (black), NOAA (orange) and NASA GISS (light blue). Graph: IPCC 2013. [Read more…] about The global temperature jigsaw

Filed Under: Aerosols, Climate modelling, Climate Science, El Nino, Instrumental Record, Oceans, statistics

  • « Go to Previous Page
  • Page 1
  • Page 2
  • Page 3
  • Page 4
  • Page 5
  • Page 6
  • Interim pages omitted …
  • Page 35
  • Go to Next Page »

Primary Sidebar

Search

Search for:

Email Notification

get new posts sent to you automatically (free)
Loading

Recent Posts

  • Unforced variations: July 2025
  • Unforced variations: Jun 2025
  • Predicted Arctic sea ice trends over time
  • The most recent climate status
  • Unforced variations: May 2025
  • Unforced Variations: Apr 2025

Our Books

Book covers
This list of books since 2005 (in reverse chronological order) that we have been involved in, accompanied by the publisher’s official description, and some comments of independent reviewers of the work.
All Books >>

Recent Comments

  • Pedro Prieto on Unforced variations: July 2025
  • Nigelj on Unforced variations: July 2025
  • Scott Nudds on Unforced variations: July 2025
  • Susan Anderson on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • jgnfld on Unforced variations: July 2025
  • Piotr on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • Paul Pukite (@whut) on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • Scott Nudds on Unforced variations: July 2025
  • Scott Nudds on Unforced variations: July 2025
  • William on Predicted Arctic sea ice trends over time
  • Piotr on Predicted Arctic sea ice trends over time
  • CherylJosie on Unforced variations: July 2025
  • William on Predicted Arctic sea ice trends over time
  • Tomáš Kalisz on Unforced variations: July 2025
  • Piotr on Unforced variations: July 2025

Footer

ABOUT

  • About
  • Translations
  • Privacy Policy
  • Contact Page
  • Login

DATA AND GRAPHICS

  • Data Sources
  • Model-Observation Comparisons
  • Surface temperature graphics
  • Miscellaneous Climate Graphics

INDEX

  • Acronym index
  • Index
  • Archives
  • Contributors

Realclimate Stats

1,368 posts

11 pages

244,229 comments

Copyright © 2025 · RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists.