[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
UN IPCC releases AR5 Synthesis Report on climate change, risks, adaptation and mitigation
November 02, 2014
The UN Intergovernmental Panel on Climate Change (IPCC) released the Synthesis Report that distills and integrates the findings of the full IPCC Fifth Assessment Report (AR5) released over the past 13 months. The report expresses with greater certainty than in previous assessments that emissions of greenhouse gases and other anthropogenic drivers have been the dominant cause of observed warming since the mid-20th century.
The report expressed with medium confidence that the period from 1983 to 2012 was likely the warmest 30-year period of the last 1,400 years in the Northern Hemisphere, where such assessment is possible. The report also noted that the globally averaged surface temperature exhibits substantial decadal and inter-annual variability. Due to this natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends. As one example, the rate of warming over the past 15 years (1998–2012; 0.05 [–0.05 to 0.15] °C per decade), which begins with a strong El Niño, is smaller than the rate calculated since 1951 (1951–2012; 0.12 [0.08 to 0.14] °C per decade). [The much discussed “pause”.]
DOE launches major 10-year project to use high performance computing for climate change research; ACME
August 24, 2014
|The ACME Project Roadmap, showing the relative sequencing of major simulation campaigns, model version development, and machine deployment. Click to enlarge.|
Eight national laboratories—Lawrence Livermore, Argonne, Brookhaven, Lawrence Berkeley, Los Alamos, Oak Ridge, Pacific Northwest and Sandia—are combining forces with the National Center for Atmospheric Research, four academic institutions and one private-sector company in a 10-year project to use high performance computing (HPC) to develop and to apply the most complete climate and Earth system model.
The project, called Accelerated Climate Modeling for Energy (ACME), is designed to accelerate the development and application of fully coupled, state-of-the-science Earth system models for scientific and energy applications. The plan is to exploit advanced software and new high performance computing machines as they become available. The initial focus will be on three climate change science drivers and corresponding questions to be answered during the project’s initial phase:
Study finds rising temperatures increase risk of unhealthy ozone levels absent sharp cuts in precursors
May 05, 2014
Ozone pollution across the continental United States will become far more difficult to keep in check as temperatures rise, according to new work led by the National Center for Atmospheric Research (NCAR). The study shows that Americans face the risk of a 70% increase in unhealthy summertime ozone levels by 2050, assuming continued greenhouse gas emissions with resultant significant warming (IPCC Scenario A2 and RCP (Representative Concentration Pathway) 8.5.)
However, the study also showed that a sharp reduction in the emissions of ozone precursors would lead to significantly decreased levels of ozone even as temperatures warm. Without those cuts, almost all of the continental United States will experience at least a few days with unhealthy air during warmer summers, the research shows. Heavily polluted locations in parts of the East, Midwest, and West Coast in which ozone already frequently exceeds recommended levels could face unhealthy air during most of the summer.
IPCC: GHG emissions accelerating despite mitigation efforts; major institutional and technological change required to keep the heat down
April 13, 2014
The UN Intergovernmental Panel on Climate Change (IPCC) released a policymaker’s summary of Working Group III’s (WG III) latest report showing that despite a growing number of climate change mitigation policies, annual anthropogenic GHG emissions grew on average by 1.0 giga tonne carbon dioxide equivalent (GtCO2eq) (2.2%) per year from 2000 to 2010 compared to 0.4 GtCO2eq (1.3%) per year from 1970 to 2000. Total anthropogenic GHG emissions were the highest in human history from 2000 to 2010 and reached 49 (±4.5) GtCO2eq/yr in 2010. The global economic crisis 2007/2008 only temporarily reduced emissions.
The increase in anthropogenic emissions comes directly from energy supply (47%); industry (30%); transport (11%); and buildings (3%) sectors, the WG reported with medium confidence. Globally, economic and population growth continue to be the most important drivers of increases in CO2 emissions from fossil fuel combustion.