Global Warming and Climate Change skepticism examined RealClimate What is the long term sensitivity to increasing CO2? What, indeed, does long term sensitivity even mean? Jim Hansen and some colleagues (not including me) have a preprint available that claims that it is around 6ºC based on paleo-climate evidence. Since that is significantly larger than the ‘standard’ climate sensitivity we’ve often talked about, it’s worth looking at in more detail. We need to start with some definitions. Traditionally, the decision to include or exclude a feedback from consideration has been based on the relevant timescales and complexity. Not coincidentally, the Charney sensitivity corresponds exactly to the sensitivity one gets with a standard atmospheric GCM with a simple mixed-layer ocean, while the Earth System sensitivity would correspond to the response in a (as yet non-existent) model that included interactive components for the cryosphere, biosphere, ocean, atmospheric chemistry and aerosols. So what does this mean for the future?
Berkeley Earth Surface Temperature (© 2011) Our ongoing research includes the study of climate variability, extreme events, and the role of the oceans. View a three page summary of our initial project objectives and early results. A two page summary of our results to date, aimed primarily at the media, is available by clicking here. More technical results, meant primarily for scientists, are presented below. Global land temperatures have increased by 1.5 degrees C over the past 250 years Berkeley Earth has just released analysis of land-surface temperature records going back 250 years, about 100 years further than previous studies. Temperature, CO2, and volcano data | More recent data | High-resolution image Land temperature with 1- and 10-year running averages. Berkeley Earth also has carefully studied issues raised by skeptics, such as possible biases from urban heating, data selection, poor station quality, and data adjustment. Human Effect Temperature, CO2, and volcano data | More recent data | High-resolution image Video
RealClimate The Physical Basis of Climate Change Not for Experts are occasional presentations from the Tyndall Centre aimed at explaining the underlying principles of climate change research. They originate as webcasts to the Tyndall (early career) Researcher Network to help train their interdisciplinary understanding of climate change research. The Physical Basis of Climate Change, Professor Corinne Le Quéré This first Not for Experts is by the Director of the Tyndall Centre, Professor Corinne Le Quéré. Professor Le Quéré explains how climate data is collected and assembled, how it is used by modellers to assess the human contribution to recent climate change, and how it is synthesized by the Intergovernmental Panel on Climate Change, and reveals the recent trends to 2011 where data is available. <div class="disqus-noscript"><a href="
A Big Picture Look at Global Warming Posted on 5 January 2012 by dana1981 Let's take a step back and have a look at what the data say about the warming of the Earth's climate. Rising Heat Content The most relevant figure when talking about global warming is the Earth's total heat content. Data from Church et al. (2011) recently updated this picture, showing that total global heat content continues its steady climb upwards. As Figure 1 shows, most of this heat (about 90%) has gone into the oceans, and the continuing rise of both global and ocean heat content is probably the best indicator that global warming hasn't even slowed down. Figure 1: Total global heat content. Rising Surface Temperature Although the rate of warming of surface air and lower troposphere temperatures appear to have slowed over the past few years, the same could be said at any virtually any point in time by cherrypicking short-term noise and ignoring the long-term trend (Figure 2). Step Change Curve Fitting Delusions Sea Ice Decline Snow Cover Extent Decline
Overview: NAS Mission The National Academy of Sciences charter commits the Academy to provide scientific advice to the government “whenever called upon” by any government department. The Academy receives no compensation from the government for its services. The National Academy of Sciences (NAS) is a private, non-profit society of distinguished scholars. Established by an Act of Congress, signed by President Abraham Lincoln in 1863, the NAS is charged with providing independent, objective advice to the nation on matters related to science and technology. The National Research Council, created under the NAS charter in 1916 by executive order of President Woodrow Wilson, extended the scope of the NAS in its advisory role. Climate change is already damaging global economy, report finds | Environment Climate change is already contributing to the deaths of nearly 400,000 people a year and costing the world more than $1.2 trillion, wiping 1.6% annually from global GDP, according to a new study. The impacts are being felt most keenly in developing countries, according to the research, where damage to agricultural production from extreme weather linked to climate change is contributing to deaths from malnutrition, poverty and their associated diseases. Air pollution caused by the use of fossil fuels is also separately contributing to the deaths of at least 4.5m people a year, the report found. The 331-page study, entitled Climate Vulnerability Monitor: A Guide to the Cold Calculus of A Hot Planet and published on Wednesday, was carried out by the DARA group, a non-governmental organisation based in Europe, and the Climate Vulnerable Forum. It was written by more than 50 scientists, economists and policy experts, and commissioned by 20 governments.
Poor UK summers may arise from global warming and Arctic ice loss - News releases - News Britain’s recent summer washout could become a regular occurrence warns a University of Sheffield climate expert who is part of an international team which has revealed climate change has shifted Arctic winds causing our extreme weather. ©iStockphoto.com/buzzanimation Following a study of the last six summers’ worth of climate data, researchers from the USA and Dr Edward Hanna of the University of Sheffield’s Department of Geography, have linked a change in summer Arctic wind patterns to global warming and an increase in the unpredictable weather. Multiple processes, known as Arctic Amplification, including record low summer sea ice extent and thickness, and loss of Greenland ice arising from increased temperatures, have been related to shifts in wind patterns contributing to out-of-season weather in Western Europe, Greenland and North America. Conversely, as the weather in the UK is getting poorer, in Greenland the unseasonal weather is warmer, drier and sunnier summers. Contact
Climate change: journalism's never-ending fight for facts | Leo Hickman | Environment The debate about climate change is dogged – possibly even defined – by its interminable, intractable tug of war over the "facts". A hand grenade is lobbed into no-man's land triggering a volley of return fire. But, when the dust settles, can anyone truly claim to have advanced their position? Of course, the art of "manufacturing doubt" has long been in the playbook of those hoping or needing to divert attention away from evidence. This week has witnessed two text-book examples of this phenomenon in action. And then we heard the extraordinary news that Alan Jones, the Australian climate sceptic shock jock, had been ordered by the country's media regulator (full ruling here) to undertake "factual accuracy" training, and to employ fact-checkers, following one of his infamous near-daily rants about the climate "hoax". Each tale hints at a different outcome: the one that got away, versus the one that got caught. Personally, I think this is all very much an open question.