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Fasten your seat belts: Climate change could add to turbulence during air travel

Flight turbulence could increase significantly under climate change, a study warns, potentially upping the risk of injury — or at least flight anxiety — for future airline passengers. Furthermore, fuel and maintenance costs for carriers could rise.

http://www.bendbulletin.com/nation/5214806-151/fasten-your-seat-belts-climate-change-could-add

An increase in atmospheric carbon dioxide concentrations could cause changes in the jet stream over the North Atlantic flight corridor, leading to a spike in air turbulence, suggests the research conducted by atmospheric scientist Paul Williams of the University of Reading.

By the middle of the century, with no effort to reduce atmospheric concentrations of carbon dioxide, the volume of airspace experiencing light turbulence would increase by about 59 percent.

Airspace experiencing severe turbulence could increase by anywhere from 36 percent to 188 percent, the study found.

“We’re particularly interested in severe turbulence, because that’s the kind of turbulence that’s strong enough to hospitalize people,” Williams told The Washington Post.

Forecasting algorithms can help pilots anticipate and avoid turbulent patches. But the research does suggest that future fliers could be in for a bumpier ride.

The paper builds on a 2013 study in the journal Nature Climate Change by Williams and colleague Manoj Joshi of the University of East Anglia, which found an increase in moderate-to-severe turbulence in the North Atlantic as a result of climate change.

The study did not investigate the effects on lighter or more severe degrees of turbulence. In the new paper, Williams expanded the study to light turbulence, and more severe conditions.

Light turbulence typically comes with only minor discomfort for passengers, perhaps an increase in nausea or anxiety. Severe turbulence has been known to cause injuries and even hospitalizations.

Williams focused on an area in the North Atlantic known for heavy air traffic, particularly between Europe and North America, and limited his simulations to winter, when turbulence is known to be at its highest.

He examined 21 different wind-related characteristics known to be indicators of air turbulence levels, including wind speed and changes in air flow direction.

The study found an increase in turbulence across the spectrum. Light turbulence was projected to increase by an average of 59 percent, light-to-moderate by 75 percent, moderate by 94 percent, moderate-to-severe by 127 percent and severe by 149 percent, although there’s substantial uncertainty associated with the more severe categories.

Williams stressed that severe turbulence would remain rare — even with the increase. But even an increase in light turbulence can cause greater wear and tear on planes or force pilots to use extra fuel redirecting their flight paths to avoid rough patches.

The increase in air turbulence may apply only to the North Atlantic, researchers not involved in the study said.

“Regional variations of this increase may be quite uncertain, particularly in the higher latitudes where other aspects of circulation change that are less well understood and more model-dependent may dominate,” said Isla Simpson, a scientist at the National Center for Atmospheric Research, in an emailed comment to The Post.

Kristopher Karnauskas, an atmospheric and oceanic sciences expert at the University of Colorado at Boulder, said the behavior of the jet stream over the Pacific may respond differently to climate change.

The study builds on an area of climate science that increasingly suggests rising global temperatures can cause changes in atmospheric airflow, including shifts in major air currents known as jet streams.

Because the equator is the warmest part of the planet, and warm air takes up more space than cold air, the atmosphere tends to be thicker around the center of Earth than at the poles. As a result, there’s a kind of downhill atmospheric slope from the equator to the poles over which air flows. While this is happening, Earth is constantly spinning, pushing airflow eastward. In the North Atlantic, the result is a jet stream — a meandering, wavy current flowing around the planet from west to east.

As the planet grows hotter, however, warming air near the surface could bring about changes in the atmospheric slope between equator and poles. Models such as the one used in Williams’ new paper have suggested that the jet stream could become stronger as a result, bringing about an increase in the types of wind patterns that lead to increased air turbulence.

Some research has already begun to detect changes in large-scale atmospheric currents. Other scientists have suggested that rapid warming in the Arctic is actually causing the jet stream to weaken.

There remains considerable uncertainty about how airflow near Earth’s surface might change in the future, Simpson said. But she said scientists are becoming more confident about the changes “that we expect to happen higher up, near the altitude where planes fly.”

Examining these issues can lead to a better understanding of the effects of climate change on aviation, Karnauskas said.

“I think it’s been decades that all of the attention has been on the impact of such industries like aviation on climate, but this is something that’s flipping it around and looking at the impact of climate on aviation,” he said. “If we can really understand the two-way street that we’re dealing with, that’s really going to help us understand ultimately how the climate will change in the future as a coupled system between the people and the atmosphere.”

India reported 1.1 million deaths due to air pollution in 2015, says a global study

http://economictimes.indiatimes.com/news/environment/pollution/india-reported-1-1-million-deaths-due-to-air-pollution-in-2015-says-a-global-study/printarticle/57145119.cms

The government here may be in denial mode on linking premature deaths to air pollution, but a new study on global air pollution by the US-based institutes claims that the India’s worsening air pollution caused some 1.1 million premature deaths in 2015 and the country now “rivals China for among the highest air pollution health burdens in the world.”

The special report on ‘global exposure to air pollution and its disease burden’, released on Tuesday, noted that the number of premature deaths in China caused by dangerous fine particulate matter, known as PM2.5, has stabilised in recent years but has risen sharply in India.

It also said that both the countries together were responsible for over half of the total global attributable deaths while India had registered an alarming increase of nearly 50% in premature deaths from particulate matter between 1990 and 2015.

Besides data analysis on air pollution, the report also carries an interactive website on the issue highlighting that 92% of the world’s population lives in the areas with unhealthy air.

“We are seeing increasing air pollution problems worldwide, and this new report and website details why that air pollution is a major contributor to early death,” said Dan Greenbaum, President of the Health Effects Institute (HEI), the global research institute that designed and implemented the study.

He said, “The trends we report show that we have seen progress in some parts of the world – but serious challenges remain.”

The State of Global Air 2017 is the first of a new series of annual reports and accompanying interactive website, designed and implemented by the Health Effects Institute in cooperation with the Institute of Health Metrics and Evaluation (IHME) at the University of Washington and the University of British Columbia.

The IHME is an independent population health research center that publishes the annual Global Burden of Diseases — a systematic scientific effort to quantify the magnitude of health loss from all major diseases, injuries, and risk factors in populations across the world. Its results are published every year in The Lancet medical journal.

“Although there are many parts of the world where air pollution has grown worse, there has also been improvement in the US and Europe. The US Clean Air Act and actions by the European Commission have made substantial progress in reducing people exposed to PM pollution since 1990,” said a statement issued by the HEI.

Referring to the study, it said, “The US has experienced a reduction of about 27% in average annual population exposures to fine particulate matter with smaller declines in Europe. Yet some 88,000 Americans and 258,000 Europeans still face increased risks of dying early due to PM levels today”.

The report noted that the highest concentrations of combustion-related fine particulate matter were in South and Southeast Asia, China and Central and Western Sub-Saharan Africa in 2015 where household solid fuel use, coal-fired power plants, transportation, and open burning of agricultural and other wastes were among the most important contributors to outdoor air pollution.

“The Global Burden of Disease leads a growing worldwide consensus – among the WHO, World Bank, International Energy Agency and others – that air pollution poses a major global public health challenges,” said Bob O’Keefe, Vice President of HEI and Chair of Clean Air Asia.

He said, “Nowhere is that risk more evident than in the rapidly growing economies of Asia.”

The study finds that increasing exposure and a growing and aging population have meant that India now rivals China for among the highest air pollution health burdens in the world, with both countries facing some 1.1 million early deaths from air pollution in 2015.

It said the long-term exposure to fine particulate matter — the most significant element of air pollution — contributed to 4.2 million premature deaths and to a loss of 103 million healthy years of life in 2015, making air pollution the 5th highest cause of death among all health risks, including smoking, diet, and high blood pressure.

India has, however, always been sceptical of such reports. Though the government here did never deny the negative impact of air pollution on human healths, it preferred not to speak about numbers.

Even recently during Budget session of the Parliament, the government had on February 6 said that there was no conclusive data to link deaths exclusively with air pollution. It, however, admitted that the air pollution could be one of the triggering factors for respiratory ailments and diseases.

“There is no conclusive data available in the country to establish direct co-relationship of death exclusively with air pollution. Health effects of air pollution are synergistic manifestation of factors which include food habits, occupational habits, socio-economic status, medical history, immunity, heredity etc. of the individuals,” said the country’s environment minister Anil Madhav Dave.

Dave, in his written response to a Parliament question in Rajya Sabha, had said, “Air pollution could be one of the triggering factors for respiratory associated ailments and diseases.”

Tube ‘higher than driving’ for air pollution, study finds

Travelling on the Underground exposes commuters to more than eight times as much air pollution as those who drive to work, a university study has found.

Monitors worn by commuters found those who travelled on the Tube were exposed to 68mg of harmful pollutant PM10, whereas car drivers had 8.2mg.

The University of Surrey study found when train windows were open, commuters were exposed to more pollutants.

Drivers were not as exposed because cars filter the pollutants out.

But although drivers are not exposed to as many pollutants, the types given out by cars are more harmful than the ones found on the Underground.

‘Environmental injustice’

The study found PM levels were highest on trains on the Victoria and Northern lines, because they all had their windows open, heightening the effect of pollutants when going through tunnels.

The study did not include people who commute on foot or cycle.

The study also found:

• Passengers on the District Line in trains with closed windows were exposed to far lower concentrations of PM than those travelling on trains with open windows on the same line
• Bus commuters were exposed to an average of 38mg of PM10, roughly half as much as Tube passengers but five times as much as cars
• The morning commute has more pollutants than the afternoon and evening journeys
• Although car drivers were the least exposed, they caused the most pollutants.

Dr Prashant Kumar, who led the study, said: “We found that there is definitely an element of environmental injustice among those commuting in London, with those who create the most pollution having the least exposure to it.

“The relatively new airtight trains with closed windows showed a significant difference to the levels of particles people are exposed to over time, suggesting that operators should consider this aspect during any upgrade of Underground trains, along with the ways to improve ventilation in underground tunnels.”

The surprising link between air pollution and Alzheimer’s disease

http://www.latimes.com/science/sciencenow/la-sci-sn-air-pollution-alzheimers-20170131-story.html

With environmental regulations expected to come under heavy fire from the Trump administration, new research offers powerful evidence of a link between air pollution and dementia risk.

For older women, breathing air that is heavily polluted by vehicle exhaust and other sources of fine particulates nearly doubles the likelihood of developing dementia, finds a study published Tuesday. And the cognitive effects of air pollution are dramatically more pronounced in women who carry a genetic variant, known as APOE-e4, which puts them at higher risk for developing Alzheimer’s disease.

In a nationwide study that tracked the cognitive health of women between the ages of 65 and 79 for 10 years, those who had the APOE-e4 variant were nearly three times more likely to develop dementia if they were exposed to high levels of air pollution than APOE-e4 carriers who were not.

Among carriers of that gene, older women exposed to heavy air pollution were close to four times likelier than those who breathed mostly clean air to develop “global cognitive decline” — a measurable loss of memory and reasoning skills short of dementia.

While scientists have long tallied the health costs of air pollution in asthma, lung disease and cardiovascular disease, the impact of air pollutants on brain health has only begun to come to light. This study gleans new insights into how, and how powerfully, a key component of urban smog scrambles the aging brain.

Published Tuesday in the journal Translational Psychiatry, the research looks at a large population of American women, at lab mice, and at brain tissue in petri dishes to establish a link between serious cognitive decline and the very fine particles of pollution emitted by motor vehicles, power plants and the burning of biomass products such as wood.

All three of these biomedical research methods suggest that exposure to high levels of fine air pollutants increases both dementia’s classic behavioral signs of disorientation and memory loss as well as its less obvious hallmarks. These include amyloid beta protein clumps in the brain and the die-off of cells in the brain’s hippocampus, a key center for memory formation.

Using air pollution standards set by the U.S. Environmental Protection Agency, researchers found significant differences on all those measures between those who breathed clean air and those exposed to pollution levels deemed unsafe.

In lab mice, breathing air collected over the 10 Freeway in Los Angeles led to brain concentrations of amyloid protein that were more dense and more likely to form dangerous clumps than breathing air that satisfied EPA standards before 2012. When lab mice were bred with a strong predisposition to develop dementia and its hallmarks, the brain differences between pollution-breathing animals and those that breathed clean air were starker.

In 2011, a study in the journal Lancet found that those who lived close to densely trafficked roads were at a far higher risk of stroke and dementia than those who lived farther away. A year later, a team led by Alzheimer’s disease researcher Dr. Samuel Gandy at Mt. Sinai in New York first established that air pollutants induced inflammation, cell death and the buildup of amyloid protein in the brains of mice.

The new study extends those findings.

Authored by geriatric and environmental health specialists at USC, the new study estimates that before the EPA set new air pollution standards in 2012, some 21% of new cases of dementia and of accelerated cognitive decline could likely have been attributed to air pollution.

There is potential legal significance to the researchers’ finding that women (and mice) who carried a genetic predisposition to developing Alzheimer’s disease were far more sensitive to air pollution’s effects. In devising pollution standards, the EPA is currently required to consider their health impact on “vulnerable populations.” The agency is also required to use its regulatory authority to take steps to protect those populations.

Air pollution has been declining steadily since the EPA promulgated new standards in 2012. But Dr. Jiu-Chiuan Chen, an environmental health specialist at USC’s Keck School of Medicine and the study’s senior author, said it’s not clear that even current standards are safe for aging brains, or for brains that are genetically vulnerable to Alzheimer’s.

The Trump administration has signaled it will look to scrap or substantially rewrite Obama administration regulations that tightened emissions from power plants and established tougher fuel efficiency standards for cars in an effort to curb climate change and reduce air pollution.

“If people in the current administration are trying to reduce the cost of treating diseases, including dementia, then they should know that relaxing the Clean Air Act regulations will do the opposite,” Chen said.

Dementia rates ‘higher near busy roads’

People who live near major roads have higher rates of dementia, research published in the Lancet suggests.

http://www.bbc.com/news/health-38506735

About 10% of dementia cases in people living within 50m of a major road could be down to traffic, the study suggests.

The researchers, who followed nearly 2m people in Canada over 11 years, say air pollution or noisy traffic could be contributing to the brain’s decline.

Dementia experts in the UK said the findings needed further investigation but were “certainly plausible”.

Nearly 50 million people around the world have dementia.

However, the causes of the disease, that robs people of their memories and brain power, are not understood.

Population growth

The study in the Lancet followed nearly two million people in the Canadian province of Ontario, between 2001 and 2012.

There were 243,611 cases of dementia diagnosed during that time, but the risk was greatest in those living closest to major roads.

Compared with those living 300m away from a major road the risk was:

• 7% higher within 50m
• 4% higher between 50-100m
• 2% higher between 101-200m

The analysis suggests 7-11% of dementia cases within 50m of a major road could be caused by traffic.

Dr Hong Chen, from Public Health Ontario and one of the report authors, said: “Increasing population growth and urbanisation have placed many people close to heavy traffic, and with widespread exposure to traffic and growing rates of dementia, even a modest effect from near-road exposure could pose a large public health burden.

“More research to understand this link is needed, particularly into the effects of different aspects of traffic, such as air pollutants and noise.”

The researchers suggest noise, ultrafine particles, nitrogen oxides and particles from tyre-wear may be involved.

However, the study looks only at where people diagnosed with dementia live. It cannot prove that the roads are causing the disease.

‘Provocative’

“This is an important paper,” says Prof Martin Rossor, the UK’s National Institute for Health Research director for dementia research.

He added: “The effects are small, but with a disorder with a high population prevalence, such effects can have important public health implications.”

Prof Tom Dening, the director of the Centre for Dementia at the University of Nottingham, said the findings were “interesting and provocative”.

He said: “It is certainly plausible that air pollution from motor exhaust fumes may contribute to brain pathology that over time may increase the risk of dementia, and this evidence will add to the unease of people who live in areas of high traffic concentration.

“Undoubtedly living in conditions of severe air pollution is extremely unpleasant and it is hard to suppose that it is good for anyone.”

The best advice to reduce the risk of dementia is to do the things that we know are healthy for the rest of the body – stop smoking, exercise and eat healthily.

Scientists disprove there was a hiatus in global warming after confirming controversial study

http://www.telegraph.co.uk/science/2017/01/05/scientists-disprove-hiatus-global-warming-confirming-controversial/

A reported pause in global warming between 1998 and 2014 was false, according to US-British research published Wednesday that confirmed the findings of a controversial US study on ocean warming.

Scientists at the University of California, Berkeley, and the University of York, England, corroborated the results of the National Oceanic and Atmospheric Administration’s (NOAA) research paper in 2015.

Their findings were reported in the US journal Science Advances.

The NOAA paper had shown ocean buoys now used to measure water temperatures tend to report slightly cooler temperatures than older ship-based systems.

The switch to buoy measurements had hidden some of the real-world warming during the 1998-2014 period, the NOAA scientists concluded.

The NOAA paper had drawn outrage from some scientists who insisted there had been a “global warming hiatus” and from critics who consider global warming a hoax.

The US House of Representatives, controlled by the Republican Party, had even demanded the NOAA scientists provide lawmakers with their email exchanges about the research.

The US government agency agreed to transmit data and respond to scientific questions but refused to hand over the emails of the study’s authors, a decision supported by scientists worried about political interference.

“Our results mean that essentially NOAA got it right, that they were not cooking the books,” said Zeke Hausfather, a graduate student in UC Berkeley’s Energy and Resources Group and lead author of the new study.

The International Panel on Climate Change, in a report published in September 2013, said the average global warming between 1951 and 2012 had been 0.12 degrees Celsius (0.22 degrees Fahrenheit) per decade.

But between 1998 and 2012, warming had amounted to only 0.07 degrees Celsius per decade, indicating a ‘global warming hiatus.’

The 2015 NOAA analysis, which was adjusted to correct for the “cold bias” of buoy measurements, found there was no detectable slowdown in ocean warming over the previous 15 years.

Reporting in the journal Science, the NOAA scientists said the oceans has actually warmed 0.12 degrees Celsius per decade since 2000, nearly twice as fast as the earlier estimates of 0.07 degrees Celsius per decade.

That brought the rate of ocean temperature rise in line with estimates for the previous 30 years, between 1970 and 1999.

The new study uses independent data from satellites and Argo floats, a worldwide satellite-based location and data collection system, as well as from buoys.

The information gathered confirmed the NOAA results in 2015 were correct, the scientists said.

“We were initially skeptical of the NOAA result, because it showed faster warming than a previous updated record from the UK Met Office,” said Kevin Cowtan of the University of York.

“So we set out to test it for ourselves, using different methods and different data. We now think NOAA got it right, and a new dataset from the Japan Meteorological Agency also agrees,” he said.

CEMENT EXAMINED AS A CARBON SINK

New research into the carbonation of cement could improve its environmental reputation, Kathryn Allen reports.

http://www.iom3.org/materials-world-magazine/news/2017/jan/04/cement-examined-a-carbon-sink

The recent study, Substantial Global Carbon Uptake by Cement Carbonation, headed by Professor Dabo Guan of the University of East Anglia, UK, claims that cement materials form a significant carbon sink.

Suggesting that only limited attention has been paid to the natural carbonation of cement materials when considering their environmental impact, the team used data on these materials to calculate estimated carbon dioxide (C02) uptake from 1930–2013. These estimations, at both regional and global levels, considered the life of cement materials including demolition and secondary uses.

Published in Nature Geoscience, the study found the estimated amount of carbon captured, from 1930-2013, offset 43% of the C02 emissions released from the production of cement. However, this does not include carbon emissions from fossil fuels used during production. In the same period, an estimated 4.5 gigatonnes of carbon was removed from the atmosphere through the carbonation of cement materials. Carbonation occurs when the calcium components of cement-based materials react with C02 in the air to form calcium carbonate.

When asked about the relevance of the findings, the team said they were important in the mitigation of climate change. Addressing the negative environmental impact of cement materials, the team pointed to the volume of cement being produced, as well as that already in existence, and its potential to absorb C02. The researchers claim 76 billion tonnes of cement was produced globally between 1930 and 2013, with 4 billion tonnes produced, mostly in China, in 2013 alone.

The team describes the vast volume of cement available to carbonate C02 as an overlooked carbon sink. Responding to this claim, Dr Charles Fentiman, Director at Shire Green Roof Substrates, noted that by using the term carbon sink the team ‘seems to be trying for a positive spin to suggest that concrete could somehow offset the C02 generated by burning of fossil fuels for other purposes, such as heating, cars and so on.’ In reality, the net emissions from cement materials is simply lower than previously thought.

Considering the potential to improve the environmental reputation of these materials, Dr Alan Maries, Visiting Professor in Environmental Technology at the University of Greenwich, UK, claimed that while this research may do so, ‘the global production of concrete already exceeds that of all other man-made materials combined by more than an order of magnitude in volume, [therefore] I doubt whether it will affect its use very much. What it will do, however, is take the pressure off cement manufacturers as villains.’

Maries also pointed out that ‘the extent of sequestration of carbon cement-containing materials has been calculated from compositional data and exposure conditions (rather than actually measured), then mathematically modelled making various assumptions. There appears to have been little field measurement to support the calculations.’ However, considering the distinguished authors of the study and the reliable sources of information, Maries suggests that the conclusions drawn are well supported. A similar concern was raised by Dr Andrew Dunster, Principle Consultant at BRE, whose view that the study contains assumptions on quality and exposure of concrete and the speed of carbonation of demolished materials makes him think potential over-estimations of carbonation levels have been made.

The team behind the study has, however, acknowledged that data is lacking in terms of how carbonation is affected by the environment, for example, by coatings and coverings of cement materials. They quote studies that show coatings such as paint can reduce carbonation by up to 10–30% as well as studies that refute this claim.

Carbonation correction coefficients, which are intended to reflect the possible effects of coatings, were used in this study to, in theory, produce accurate results. However, the reliance on estimations in this study has not gone unnoticed.

The researchers hope their findings can be applied practically to future developments. Buildings made of cement materials can be designed to maximize carbonation and recycling and reuse of cement materials will prevent the absorbed carbon from being released back into the atmosphere. Discussing potential applications of the findings, Guan said, ‘We suggest that if carbon capture and storage technology were applied to cement process emissions, the produced cements might represent a source of negative C02 emissions. Policymakers might also investigate a way to increase the completeness and rate of carbonation of cement waste.’

Air pollution costs trillions

Premature deaths due to air pollution cause annual global costs of about US$225 billion in lost work days, and more than US$5 trillion in welfare losses, according to a new study.

http://airclim.org/acidnews/air-pollution-costs-trillions

Exposure to air pollution increases the risk of contracting cancers and heart, lung and respiratory diseases. According to the latest available estimates by the World Health Organization (WHO), 5.5 million premature deaths worldwide, or 1 in every 10 deaths, in 2013 were attributable to indoor and outdoor air pollution.

A joint study, entitled “The Cost of Air Pollution: Strengthening the economic case for action”, published by the World Bank and the Institute for Health Metrics and Evaluation, has estimated the costs of premature deaths related to air pollution.

Using the WHO estimates of premature mortality attributable to air pollution, the study valued the economic costs following two different approaches: Firstly a welfare-based approach that monetizes the increased fatality risk from air pollution according to individuals’ willingness to pay, and secondly an income-based approach that equates the financial cost of premature mortality with the present value of forgone lifetime earnings.

In 2013, the cost to the world’s economy of welfare losses due to exposure to ambient and household air pollution amounted to some US$5.11 trillion. In terms of magnitude, welfare losses in South Asia and East Asia and the Pacific were the equivalent of about 7.5 per cent of the regional gross domestic product (GDP), while in Europe and North America they were equal to respectively 5.1 and 2.8 per cent of GDP. At the low end, losses were still equal to 2.2 per cent of GDP in the Middle East and North Africa.

It is pointed out that the full costs of air pollution to society are even greater than is reported in the study. Examples of other costs not included in this report are the costs of illnesses (e.g. hospital care, medication), reduced output of agricultural crops, damage to natural ecosystems and cultural heritage, and lowered economic competitiveness of growing cities.

On top of being a major health risk, air pollution is also a drag on development. By causing illness and premature death, air pollution reduces the quality of life. By causing a loss of productive labour, it also reduces productivity and incomes.

According to the study, annual labour income losses cost the equivalent of 0.83 per cent of the gross domestic product (GDP) in South Asia. In East Asia and the Pacific, where the population is ageing, labour income losses represent 0.25 per cent of GDP, while in Sub-Saharan Africa, where air pollution impairs the earning potential of younger populations, annual labour income losses represent 0.61 per cent of GDP.

“Air pollution is a challenge that threatens basic human welfare, damages natural and physical capital, and constrains economic growth. We hope this study will translate the cost of premature deaths into an economic language that resonates with policy makers so that more resources will be devoted to improving air quality. By supporting healthier cities and investments in cleaner sources of energy, we can reduce dangerous emissions, slow climate change, and most importantly save lives,” said Laura Tuck, Vice President for Sustainable Development at the World Bank.

Christer Ågren

The report: https://openknowledge.worldbank.org/handle/10986/25013

World Bank press release, 8 September 2016: http://www.worldbank.org/en/news/press-release/2016/09/08/air-pollution-…

Rise in atmospheric CO2 slowed by green vegetation

The growth in the amount of CO2 in the Earth’s atmosphere has been slowed by the increased ability of plants to soak up the gas.

http://www.bbc.com/news/science-environment-37909361

A new study says that green vegetation has helped offset a large fraction of human related carbon emissions between 2002 and 2014.

Plants and trees have become more absorbent say the authors, because of so much extra CO2 in the atmosphere.

The slowdown, though, can’t keep pace with the overall scale of emissions.

Over the past 50 years, the amount of CO2 absorbed by the Earth’s oceans, plants and vegetation has doubled and these carbon sinks now account for about 45% of the gas emitted each year because of human activities.

Researchers now report that since the start of the 21st century there has been a significant change in the amount of carbon dioxide taken up by the plants and trees. The new analysis suggests that between 2002 and 2014 the amount of human caused CO2 remaining in the atmosphere declined by around 20%.

Reports earlier this year indicated that there has been an increase in the number of trees and plants growing on the Earth, the so-called greening of the planet. But the authors of this new study believe that this isn’t the main cause of the slowdown in the rise of CO2.

Image copyright BERKELEY LAB Image caption The black line is the observed growth rate and the beige line is the modelled rate. The blue line indicates no increasing trend between 2002 and 2014.

“There have been reports of the greening of the land surface but what we found was that was of secondary importance to the direct effect of CO2 fertilisation on the plants that are already there,” lead author Dr Trevor Keenan told BBC News.

“We have a huge amount of vegetation on the Earth and that was being fertilised by CO2 and taking in more CO2 as a result.”

Another important element in the story is the impact of a hiatus in global temperature increases on the behaviour of plants. Between 1998 and 2012 temperatures went up by less than in previous decades. This has impacted the respiration of vegetation.

“The soils and ecosystem are respiring so as temperatures increase they respire more, releasing more CO2 into the atmosphere,” said Dr Keenan.

“In the past decade or so there hasn’t been much of an increase in global temperatures, so that meant there wasn’t much of an increase in respiration and carbon release so that was fundamentally different in the past decade or so compared to previous periods.”

One consequence of a warming world that has been expected to increase was the number of droughts around the world. However, this new study suggests that, on a global scale, there has been little or no change in the prevalence of drought over recent decades.

Overall though the slowdown caused by vegetation hasn’t stemmed the total rise of carbon which has now passed the symbolically important level of 400 parts per million (ppm) in the atmosphere.

Image copyright SPL Image caption Green vegetation has limited the growth of CO2 in the atmosphere over the last decade

“This study highlights just how sensitive the natural environment is to a changing climate and how important it is to protect natural vegetation so it continues to absorb part of our carbon emissions,” said Prof Corinne Le Quéré, director of the Tyndall Centre at the University of East Anglia, who wasn’t involved in the study.

“Fundamentally, though, the carbon sinks help but their help is not enough to stop the planet getting warmer – far from that – carbon emissions have to drop to almost zero to stop global warming.”

One of the big lessons from the new report is that land carbon sinks are not set in stone and do have the potential to change over time. If they could be managed properly, it might help some countries to cut their emissions and limit climate change.

The authors of the study say that the pause in the growth of atmospheric carbon will almost certainly be a temporary phenomenon. As temperatures rise, these green sinks could in fact become sources of CO2.

“Now we are seeing plants slow down the rate of climate change,” said Dr Keenan.

“But if we are not careful and we don’t do anything about climate change all that CO2 could be put back in the atmosphere later and that would really accelerate the rate of warming.

“It may be hitting the brakes right now but it can really punch the accelerator later.”

The study has been published in the journal Nature Communications

300 million children breathe heavily toxic air: UNICEF

Some 300 million children live with outdoor air so polluted it can cause serious physical damage, including harming their developing brains, the United Nations said in a study released Monday.

Nearly one child in seven around the globe breathes outdoor air that is at least six times dirtier than international guidelines, according to the study by the UN Children’s Fund, which called air pollution a leading factor in child mortality.

UNICEF published the study, “Clear the Air for Children,” a week before the annual UN climate-change talks, with the upcoming round to be hosted by Morocco on November 7-18.

The agency, which promotes the rights and well-being of children, is pushing for world leaders to take urgent action to reduce air pollution in their countries.

“Air pollution is a major contributing factor in the deaths of around 600,000 children under five every year, and it threatens the lives and futures of millions more every day,” said Anthony Lake, executive director of UNICEF.

“Pollutants don’t only harm children’s developing lungs. They can actually cross the blood-brain barrier and permanently damage their developing brains and, thus, their futures. No society can afford to ignore air pollution,” Lake said.

Toxic air is a drag on economies and societies, and already costs as much as 0.3 percent of global gross domestic product, the broad measure of economic activity, UNICEF said.

Those costs are expected to increase to about one percent of GDP by 2060, it said, as air pollution in many parts of the world worsens.

UNICEF points to satellite imagery which it says confirms that about two billion children live in areas where outdoor air pollution exceeds minimum air-quality guidelines set by the World Health Organization.

The air is poisoned by vehicle emissions, fossil fuels, dust, burning waste and other airborne pollutants, it said.

South Asia has the largest number of children living in such areas at about 620 million, followed by Africa with 520 million and the East Asia and Pacific region with 450 million.

The study also looked at indoor air pollution, typically caused by burning coal and wood for cooking and heating.

Together, outdoor and indoor air pollution are directly linked to pneumonia and other respiratory diseases that account for almost one death in 10 in children under the age of five, or nearly 600,000 children, making air pollution a leading danger to children’s health, UNICEF said.

The agency noted that children are more susceptible than adults to indoor and outdoor air pollution because their lungs, brains and immune systems are still developing and their respiratory tracts are more permeable.

Children breathe twice as quickly as adults and take in more air relative to their body weight.

The most vulnerable to illnesses caused by air pollution are children living in poverty, who tend to have poorer health and little access to health services.

– Better protect children –

To combat these noxious effects, UNICEF will call on the world’s leaders at the UN’s 22nd meeting on climate change in Marrakesh, known as COP22, to take urgent action to better protect children.

“Reducing air pollution is one of the most important things we can do for children,” UNICEF said in its report.

At the government level, UNICEF said steps should be taken to reduce fossil-fuel emissions and increase investments in sustainable energy and low-carbon development.

The agency, noting that air quality can fluctuate rapidly, also called for better monitoring of air pollution to help people minimize their exposure.

Children’s access to good-quality healthcare needs to be improved and breastfeeding in the child’s first six months should be encouraged to help prevent pneumonia.

Policymakers should “develop and build consensus on children’s environmental health indicators,” the report urged.

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