Archive for the ‘climate change – global warming’ Category

International co-operation works: the healing of the ozone layer

December 4, 2018
Ozone layer finally healing after damage caused by aerosols, UN says https://www.theguardian.com/environment/2018/nov/05/ozone-layer-healing-after-aerosols-un-northern--hemisphere Fiona  HarveyEnvironment correspondent
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“Climate change, nuclear power, and the adaptation–mitigation dilemma”

December 4, 2018

“Climate change, nuclear power, and the adaptation–mitigation dilemma”  https://nuclearexhaust.wordpress.com/2018/11/04/climate-change-nuclear-power-and-the-adaptation-mitigation-dilemma/ Natalie Kopytko and JohnPerkins The University of York, Heslington, York YO10 5DD, UK The Evergreen State College, 1806 24th Avenue NW, Olympia, WA 98502, USA, Available online 30 October 2010.

https://www.sciencedirect.com/science/article/pii/S0301421510007329?via%3Dihub

Abstract
Many policy-makers view nuclear power as a mitigation for climate change. Efforts to mitigate and adapt to climate change, however, interact with existing and new nuclear power plants, and these installations must contend with dilemmas between adaptation and mitigation. This paper develops five criteria to assess the adaptation–mitigation dilemma on two major points:

(1) the ability of nuclear power to adapt to climate change and

(2) the potential for nuclear power operation to hinder climate change adaptation.

Sea level rise models for nine coastal sites in the United States, a review of US Nuclear Regulatory Commission documents, and reports from France’s nuclear regulatory agency provided insights into issues that have arisen from sea level rise, shoreline erosion, coastal storms, floods, and heat waves. Applying the criteria to inland and coastal nuclear power plants reveals several weaknesses.

Safety stands out as the primary concern at coastal locations, while inland locations encounter greater problems with interrupted operation. Adapting nuclear power to climate change entails either increased expenses for construction and operation or incurs significant costs to the environment and public health and welfare. Mere absence of greenhouse gas emissions is not sufficient to assess nuclear power as a mitigation for climate change.

Research Highlights
►The adaptation-mitigation criteria reveal nuclear power’s vulnerabilities. ►Climate change adaptation could become too costly at many sites. ►Nuclear power operation jeopardizes climate change adaptation. ►Extreme climate events pose a safety challenge.     end quote of abstract. see original link above.

Annabel Crabb outlines the demise of Australia’s climate policy in 7 killings

November 3, 2018

Australia’s recent climate change policy: A brief history of seven killings http://www.abc.net.au/news/2018-08-23/climate-change-policy-a-brief-history-of-seven-killings/10152616, By Annabel Crabb  

The story starts in 1997, when the brand-new Howard government (sweating through a brief and cock-up-infested first term during which it lost a series of ministers and most of the margin with which it had wrested power from Paul Keating) sends its environment minister, Robert Hill, to Japan for the seminal Kyoto Climate Summit.

At the summit, Senator Hill negotiates generous terms for his country in the global deal; Australia emerged with large concessions for its agricultural activities and is one of only three countries permitted to increase its emissions under the deal.

Senator Hill is welcomed home as a conquering hero.

However, over the years enthusiasm for the compact is replaced within the government by scepticism.

First casualty (more…)

What the IPCC Report 2018 says about nuclear power

November 3, 2018
Nuclear energy can increase the risks of proliferation (SDG 16), have negative environmental effects (e.g., for water use, SDG 6), and have mixed effects for human health when replacing fossil fuels (SDGs 7 and 3) (see Table 5.2)   (CH 5 p 23) )  http://report.ipcc.ch/sr15/pdf/sr15_chapter5.pdf
Nuclear power increases its share in most 1.5°C pathways by 2050, but in some pathways both the absolute capacity and share of power from nuclear generators declines (Table 2.15). There are large differences in nuclear power between models and across pathways (Kim et al., 2014; Rogelj et al., 2018). One of the reasons for this variation is that the future deployment of nuclear can be constrained by societal preferences assumed in narratives underlying the pathways (O’Neill et al., 2017; van Vuuren et al., 2017b). Some 1.5°C pathways no longer see a role for nuclear fission by the end of the century, while others project over 200 EJ yr–1 of nuclear power in 2100 (Figure 2.15).   CH 2

Chapter 5 – Table 5.3    In spite of the industry’s overall safety track record, a non-negligible risk for accidents in nuclear power plants and waste treatment facilities remains. The long-term storage of nuclear waste is a politically fraught subject, with no large-scale long-term storage operational worldwide. Negative impacts from upsteam uranium mining and milling are comparable to those of coal, hence replacing fossil fuel combustion by nuclear power would be neutral in that aspect. Increased occurrence of childhood leukaemia in populations living within 5 km of nuclear power plants was identified by some studies, even though a direct causal relation to ionizing radiation could not be established and other studies could not confirm any correlation (low evidence/agreement in this issue).   Table 5.3  http://report.ipcc.ch/sr15/pdf/sr15_chapter5_table5_3.pd

Politicians, media, the world – does no-one care about the unfolding horror of the melting Arctic?

October 9, 2018

It’s not only summer weather that is changing. Earlier this year, one study showed that when the Arctic is unusually warm, extreme winter weather is two-to-four times more likely in the eastern U.S.

Think of the Arctic as our early warning system, a big screaming alarm that is alerting us to the fact that the planet we will live on tomorrow is nothing like the planet we lived on yesterday, and we better get ready.

The Melting Arctic Is a Real-Time Horror Story — Why Doesn’t Anyone Care?https://www.rollingstone.com/politics/politics-news/arctic-ice-melting-716647/ This summer’s epic wildfires and other extreme weather events have a root cause By 

Is nuclear power REALLY a worthwhile method of dealing with climate change?

October 9, 2018

Climate change, nuclear power, and the adaptation–mitigation dilemma https://www.sciencedirect.com/science/article/pii/S0301421510007329  NatalieKopytkoaJohnPerkins  

Abstract

Many policy-makers view nuclear power as a mitigation for climate change. Efforts to mitigate and adapt to climate change, however, interact with existing and new nuclear power plants, and these installations must contend with dilemmas between adaptation and mitigation. This paper develops five criteria to assess the adaptation–mitigation dilemma on two major points:

(1) the ability of nuclear power to adapt to climate change and

(2) the potential for nuclear power operation to hinder climate change adaptation.

Sea level rise models for nine coastal sites in the United States, a review of US Nuclear Regulatory Commission documents, and reports from France’s nuclear regulatory agency provided insights into issues that have arisen from sea level rise, shoreline erosion, coastal storms, floods, and heat waves. Applying the criteria to inland and coastal nuclear power plants reveals several weaknesses. Safety stands out as the primary concern at coastal locations, while inland locations encounter greater problems with interrupted operation.

Adapting nuclear power to climate change entails either increased expenses for construction and operation or incurs significant costs to the environment and public health and welfare. Mere absence of greenhouse gas emissions is not sufficient to assess nuclear power as a mitigation for climate change.

Research Highlights

►The adaptation-mitigation criteria reveal nuclear power’s vulnerabilities. ►Climate change adaptation could become too costly at many sites. ►Nuclear power operation jeopardizes climate change adaptation. ►Extreme climate events pose a safety challenge.

The Impact of Climate Change on Nuclear Power Supply

October 9, 2018

Kristin Linnerud*, Torben K. Mideksa** and Gunnar S. Eskeland***

A warmer climate may result in lower thermal efficiency and reduced load—including shutdowns—in thermal power plants. Focusing on nuclear power plants, we use different European datasets and econometric strategies to identify these two supply-side effects. We find that a rise in temperature of 1C reduces the supply of nuclear power by about 0.5% through its effect on thermal efficiency; during droughts and heat waves, the production loss may exceed 2.0% per degree Celsius because power plant cooling systems are constrained by physical laws, regulations and access to cooling water. As climate changes, one must consider measures to protect against and/or to adapt to these impacts.

  1. INTRODUCTION Climate change may affect thermal power plants in two ways. Firstly, increased ambient temperature reduces the efficiency of thermal power plants in turning fuel into electricity (i.e. lowers the ratio of electricity produced to the amount of fuel used in producing it). For example, the difference in sea temperature between the Black Sea and the Mediterranean Sea will play a role in where Turkey builds 10 planned nuclear plants because the efficiency of these plants is negatively related to the temperature of the coolant (Durmayaz and Sogut, 2006).Secondly, at high ambient temperatures, the load of a thermal power plant may be limited by maximum condenser pressure, regulations on maximum allowable temperature for return water or by reduced access to water as a result of droughts. For example, during the 2003 summer heat wave in Europe, more than 30 nuclear power plant units in Europe were forced to shut down or reduce their power production (IAEA 2004; Zebisch et al., 2005; Rebetez et al., 2009; Koch and Vo¨gele, 2009). Our analysis focuses on these two temperature-induced impacts: reduced efficiency and increased frequency of shutdowns.

Although all thermal power plants are exposed to these two impacts, nuclear power plants are especially vulnerable. The average efficiency is lower and the water requirement per electricity output is higher in nuclear power plants compared to most other thermal power plants. More importantly, energy disruptions at nuclear power plants may cause a threat to energy supply security since each nuclear reactor accounts for a considerable amount of power and nuclear reactors are typically located in the same geographical area with access to the same source of cooling water (Vo¨gele, 2010).

The two climate impacts have been addressed in the climate and energy literature. The 4th Assessment report of the Intergovernmental Panel on Climate Change (IPCC 2007, p. 556) reported that climate change could have a negative impact on thermal power production since the availability of cooling water may be reduced.

……..Cooling water shortages or regulatory limitations on the increase in water temperature put further restrictions on a nuclear power plant’s operations.8 The temperature of the returned cooling water is most often subject to regulations. The allowable return temperature varies depending on the source of the water, ambient conditions and local regulations. As the temperature of river or sea water rises, the water will be able to absorb less heat before exceeding the maximum allowable temperature limit for return water. In such circumstances, the plant must reduce power production until the return temperature is below the limit.

……Droughts may also reduce plants’ access to cooling water, and plants in drought-prone areas are especially vulnerable to climate change.

In sum, as ambient temperature rises, production of electricity at nuclear power plants may decrease as a result of both efficiency losses and cooling system …….https://bwl.univie.ac.at/fileadmin/user_upload/lehrstuhl_ind_en_uw/lehre/ws1213/SE_Energy_WS12_13/The_Impact_of_Climate_Change_on_Nuclear_Power_Supply.pdf

Earth’s climate would increase by 4 °C, compared to pre-industrial levels, before the end of 21st century.

October 9, 2018

Earth’s climate to increase by 4 degrees by 2084 https://www.eurekalert.org/pub_releases/2018-05/ioap-ect052318.php  INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

A collaborative research team from China has published a new analysis that shows the Earth’s climate would increase by 4 °C, compared to pre-industrial levels, before the end of 21st century.

To understand the severity of this, consider the Paris Agreement (https://unfccc.int/process/the-paris-agreement/what-is-the-paris-agreement) of the United Nations. It’s a global effort to prevent an increase of 2°C. Nearly every country on the planet–the United States is the only country to withdraw–has agreed to work to prevent the catastrophic effects of two degrees of warming.

The researchers published their analysis projecting a doubling of that increase in Advances in Atmospheric Sciences (https://link.springer.com/article/10.1007/s00376-018-7160-4 ) on May 18, 2018.

“A great many record-breaking heat events, heavy floods, and extreme droughts would occur if global warming crosses the 4 °C level, with respect to the preindustrial period,” said Dabang Jiang, a senior researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences. “The temperature increase would cause severe threats to ecosystems, human systems, and associated societies and economies.”

In the analysis, Jiang and his team used the parameters of scenario in which there was no mitigation of rising greenhouse gas emissions. They compared 39 coordinated climate model experiments from the fifth phase of the Coupled Model Intercomparison Project (https://www.wcrp-climate.org/wgcm-cmip), which develops and reviews climate models to ensure the most accurate climate simulations possible.

They found that most of the models projected an increase of 4°C as early as 2064 and as late as 2095 in the 21st century, with 2084 appearing as the median year.

This increase translates to more annual and seasonal warming over land than over the ocean, with significant warming in the Arctic. The variability of temperature throughout one year would be lower in the tropics and higher in polar regions, while precipitation would most likely increase in the Arctic and in the Pacific. These are the same effects that would occur under 1.5°C or 2°C increases, but more severe.

“Such comparisons between the three levels of global warming imply that global and regional climate will undergo greater changes if higher levels of global warming are crossed in the 21st century,” wrote Jiang.

The researchers continue to investigate the changes associated with 4°C of global warming in extreme climates.

“Our ultimate goal is to provide a comprehensive picture of the mean and extreme climate changes associated with higher levels of global warming based on state-of-the art climate models, which is of high interest to the decision-makers and the public,” said Jiang.

Researchers from the Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences, the Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters at the Nanjing University of Information Science & Technology, the Joint Laboratory for Climate and Environmental Change at Chengdu University of Information Technology, and the University of Chinese Academy of Sciences contributed to this study.

This work was supported by the National Basic Research Program of China and the National Natural Science Foundation of China.

Climate change urgency: the Arctic is heating

April 2, 2018

Antarctic ice sheet loss and sea level rise Guardian[Excellent graphs]  1 March 2018 

dana1981 more https://www.theguardian.com/environment/climate-consensus-97-per-cent/2018/mar/01/decisions-today-will-decide-antarctic-ice-sheet-loss-and-sea-level-rise

A new study looks at how much global sea level will continue to rise even if we manage to meet the Paris climate target of staying below 2°C hotter than pre-industrial temperatures. The issue is that sea levels keep rising for several hundred years after we stabilize temperatures, largely due to the continued melting of ice sheets in Antarctica and Greenland from the heat already in the climate system.

The study considered two scenarios. In the first, human carbon pollution peaks somewhere between 2020 and 2035 and falls quickly thereafter, reaching zero between 2035 and 2055 and staying there. Global temperatures in the first scenario peak at and remain steady below 2°C. In the second scenario, we capture and sequester carbon to reach net negative emissions (more captured than emitted) between 2040 and 2060, resulting in falling global temperatures in the second half of the century.

The authors found that global average sea level will most likely rise by about 1.3 meters by 2300 in the first scenario, and by 1 meter in the second. However, there is large uncertaintydue to how little we understand about the stability of the large ice sheets in Greenland and especially Antarctica. At the high end of possible ice sheet loss, we could see as much as 4.5 meters of sea level rise by 2300 in the first scenario, and close to 3 meters in the second scenario.

The study also shows that it’s critical that our carbon pollution peaks soon. Each 5-year delay – a peak in 2025 instead of 2020, for example – most likely adds 20 cm of sea level rise by 2300, and could potentially add a full meter due to the uncertainty associated with the large ice sheets:

we find that a delay of global peak emissions by 5 years in scenarios compatible with the Paris Agreement results in around 20 cm of additional median sea-level rise in 2300 … we estimate that each 5 years of delay bear the risk of an additional 1 m of sea-level rise by 2300 … Delayed near-term mitigation action in the next decades will leave a substantial legacy for long-term sea-level rise.

And remember, this is all for scenarios in which we meet the Paris climate targets, which we’re currently not on pace to achieve. If we miss the Paris targets, sea levels will rise higher yet.

Another new study, published in the Proceedings of the National Academy of Sciences, found that sea level rise has been accelerating. If the rate of acceleration continues – which the lead author notes is a conservative estimate – we would see an additional 65 cm (close to a meter above pre-industrial sea level) of sea level rise by 2100.

Yet another new study published in The Cryosphere using satellite data found that while the East Antarctic Ice Sheet has remained stable in recent years, ice loss from the West Antarctic Ice Sheet has accelerated. Antarctica is now discharging 1.93 trillion tons of ice each year, up from about 1.89 trillion tons per year in 2008. When accounting for snow accumulation, the continent is losing about 183 billion tons of ice per year – enough to raise sea levels by about 3 to 5 millimeters per decade by itself. The melting of the Greenland Ice Sheet is likewise accelerating and is now responsible for about 25% of annual sea level rise (8.5 millimeters per decade).

Meanwhile, the Arctic has been remarkably warm in February – as much as 35°C hotter than average in some areas. In mid-winter, when sea ice should be growing, in the Bering Sea it’s instead shrinking.

The hot Arctic is important because the temperature difference between the Arctic and lower latitudes is one of the main forces that keeps the jet stream moving steadily west-to-east. With a hot Arctic, the jet stream is weakened, leading to weird weather in the USA and Europe. As a result, the western states have been experiencing relatively quite cold temperatures, while the US east coast has been unseasonably hot.

To sum up, ice sheet melt is accelerating, as in turn is sea level rise. Even if we manage to achieve the Paris target of less than 2°C global warming above pre-industrial temperatures, we’re likely to eventually see more than a meter of sea level rise, and potentially several meters. The longer we take to reach peak carbon pollution in the coming years, the higher the oceans will rise. Disappearing sea ice in the rapidly-warming Arctic also appears to be causing increasingly weird and extreme weather in places like America and Europe.

Explaining Extreme Events from a Climate Perspective

April 2, 2018

American Meteorological Society, Dec 17, 

This BAMS special report presents assessments of how human-caused climate change may have affected the strength and likelihood of individual extreme events.

This sixth edition of explaining extreme events of the previous year (2016) from a climate perspective is the first of these reports to find that some extreme events were not possible in a preindustrial climate. The events were the 2016 record global heat, the heat across Asia, as well as a marine heat wave off the coast of Alaska. While these results are novel, they were not unexpected. Climate attribution scientists have been predicting that eventually the influence of human-caused climate change would become sufficiently strong as to push events beyond the bounds of natural variability alone. It was also predicted that we would first observe this phenomenon for heat events where the climate change influence is most pronounced. Additional retrospective analysis will reveal if, in fact, these are the first events of their kind or were simply some of the first to be discovered. Read More

DOWNLOAD EXPLAINING EXTREME EVENTS OF 2016
Download high resolution version (46 MB).  https://www.ametsoc.org/ams/index.cfm/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events-from-a-climate-perspective/