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Topics - Lennart van der Linde

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Hansen et al publish new draft paper on the Burden for Young People and the need for negative emissions:
https://www.theguardian.com/environment/2016/oct/03/global-temperature-climate-change-highest-115000-years

Abstract
The rapid rise of global temperature that began about 1975 continues at a mean rate of about 0.18°C/decade, with the current annual temperature exceeding +1.25°C relative to 1880-1920. Global temperature has just reached a level similar to the mean level in the prior interglacial (Eemian) period, when sea level was several meters higher than today, and, if it long remains at this level, slow amplifying feedbacks will lead to greater climate change and consequences.  The growth rate of climate forcing due to human-caused greenhouse gases (GHGs) increased over 20% in the past decade mainly due to resurging growth of atmospheric CH4, thus making it increasingly difficult to achieve targets such as limiting global warming to 1.5°C or reducing atmospheric CO2 below 350 ppm.  Such targets now require “negative emissions”, i.e., extraction of CO2 from the atmosphere.  If rapid phasedown of fossil fuel emissions begins soon, most of the necessary CO2 extraction can take place via improved agricultural and forestry practices, including reforestation and steps to improve soil fertility and increase its carbon content.  In this case, the magnitude and duration of global temperature excursion above the natural range of the current interglacial (Holocene) could be limited and irreversible climate impacts could be minimized.  In contrast, continued high fossil fuel emissions by the current generation would place a burden on young people to undertake massive technological CO2 extraction, if they are to limit climate change.  Proposed methods of extraction such as bioenergy with carbon capture and storage (BECCS) or air capture of CO2 imply minimal estimated costs of 104-570 trillion dollars this century, with large risks and uncertain feasibility.  Continued high fossil fuel emissions unarguably sentences young people to either a massive, possibly implausible cleanup or growing deleterious climate impacts or both, scenarios that should provide both incentive and obligation for governments to alter energy policies without further delay.

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Glaciers / Glaciers worldwide decline faster than ever
« on: August 04, 2015, 08:36:59 AM »
Zemp et al 2015:
http://www.ingentaconnect.com/content/igsoc/jog/pre-prints/content-ings_jog_15j017

Abstract
"Observations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (~42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (~5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable."

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From TEDx Rotterdam in 2011, with some nice footage on the melting Arctic:


Climate journalist and explorer Bernice Notenboom will host a six part international TV-documentary production on climate tipping points premiering on Dutch national television on September 8 this year and on the US Weather Channel coming October:
http://press.weather.com/press-releases/the-weather-channel-travels-to-the-far-corners-of-the-earth-to-explore-the-world-s-tipping-points/

She "will be joined by a number of leading international environmental scientists in each episode such as Torben Christensen, Peter Cox, Dorthe Dahl-Jensen, Matthew England, James Hansen, Tim Lenton, Yadvinder Malhi, Konrad Steffen, Katey Walker, Jay Zwally, and more. Stu Ostro, senior meteorologist for The Weather Channel, will serve as contributing science editor on the project.

The Weather Channel owns the U.S. rights as the sole U.S. network to air the series. The global partnership includes international networks NHK Japan, ARD Group Germany, Canvas Belgium, VPRO Holland, and The Australia Network."

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Science / NOAA's State of the Climate 2012
« on: August 07, 2013, 01:18:56 PM »
The Guardian reports:
http://www.theguardian.com/world/2013/aug/06/noaa-report-arctic-ice-climate-change

'The biggest changes in the climate in 2012 were in the Arctic and in Greenland, said the report, which is an annual exercise by a team of American and British scientists. The Arctic warmed at about twice the rate of lower latitudes, the report found. By June 2012, snow cover had fallen to its lowest levels since the record began. By September 2012, sea-ice cover had retreated to its lowest levels since the beginning of satellite records, falling to 1.32 million square miles.

That was, the report noted, a whopping 18% lower than the previous low, set in 2007, and a staggering 54% lower than the mark for 1980.

The changes were widespread on land as well, with record warm permafrost temperatures in Alaska and in the Canadian Arctic, the report's authors noted. On 11 July last year, Greenland experienced surface melting on 97% of the ice sheet. The record-breaking events indicate an era of "new normal" for the climate, the researchers said.'

The report and other materials can be found at:
http://www.ncdc.noaa.gov/bams-state-of-the-climate/2012.php

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