City leaders invited to discover how real-time monitoring of urban greenhouse gases can help tackle climate change

Meeting Announcement

OPTICA

City and regional government leaders and policymakers are being invited to discover how real-time monitoring of urban greenhouse gases (GHGs) can help them in their efforts to tackle climate change.

The Cities are the Key to the Climate Solution Summit, organised by the Global Environmental Measurement and Monitoring (GEMM) Initiative, will showcase a pilot urban air quality monitoring project in Glasgow as the city hosts the COP26 climate change conference in November.

The project is establishing a dense network of 25 sensors monitoring levels of GHGs and particulate matter across Glasgow in real-time.

Data from the network of sensors, coupled with ‘inverse modelling’, can help to identify sources of GHG emissions, providing city leaders and policymakers with information to help them decide on climate change policies and observe their impact almost immediately.

Currently, most data on GHG emissions is calculated based on consumption of fossil fuels and is only available months or years later, whereas sensor networks offer the opportunity for direct, real-time atmospheric observations.

The GEMM Initiative-supported project is a collaboration between the University of Strathclyde, Glasgow City Council, Stanford University, the University of California at Berkeley (UC Berkeley), Optica (formerly OSA), the American Geophysical Union, the Met Office and the National Physical Laboratory.

The Cities are the Key to the Climate Solution summit will showcase these new technologies and methodologies for the monitoring of GHG emissions and air pollutants in real-time, consider the economic and legal perspectives of adopting this approach and will feature a roundtable discussion on the opportunities and challenges cities face in meeting GHGs and air pollution reduction goals.

The hybrid summit – online and in-person – will take place on 3 November in Strathclyde’s Technology & Innovation Centre and feature speakers including: Susan Aitken, Leader of Glasgow City Council, David Miller, Director of International Diplomacy at C40 Cities, Professor Donna Strickland, 2018 Nobel Laureate in Physics, and Professor Guy Brasseur of the Max Planck Institute for Meteorology.

Optica and AGU – international scientific societies partnering under the GEMM Initiative – are working with policymakers worldwide on new technology and scientific developments for local impact. 

“We want to make city leaders aware of this technology, the opportunities it brings and encourage them to set up their own sensor network projects,” said Tom Baer, co-lead and Director of Stanford Photonics Research Center at Stanford University, USA.

“Recent deployments of low-cost, high-density sensors across several cities around the world are demonstrating the utility of mapping GHG and air pollution levels in real time.”

University of Strathclyde Professor Allister Ferguson, co-lead of the project, said: “Cities account for more than 70% of all GHG emissions and therefore have a key role to play in taking measures to tackle climate change. Indeed, many cities around the world are already committing to action and have set net-zero targets, including Glasgow.

“Analyses of COVID-19 emissions reductions during government stay-at-home orders have shown that determining the emission contributions from various source sectors with detailed mapping and timing across the full daily cycle are possible and can provide invaluable information on governmental policies affecting GHG emission levels.”

The Glasgow pilot project uses GHG sensors developed by Professor Ron Cohen at UC Berkeley which cost a fraction of the price of traditional monitoring stations.

Professor Cohen has been operating a large network of sensors in the San Francisco Bay area for eight years as part of the BEACO2N project. During the ‘shelter-in-place’ orders imposed in California as a result of COVID-19 he was able to see how the decrease in vehicular traffic had on CO2 emissions in the area.

He said: “When the COVID ‘shelter-in-place’ order began in California, almost immediately there was a tremendous reduction in CO2 emissions in the San Francisco Bay Area. Regional carbon dioxide emissions dropped by 25%, almost all of it due to a nearly 50% drop in road traffic.

“It really allowed us to test our ideas of how much of the CO2 is from industry and how much is from cars. This is what it would look like for CO2 if we electrified the vehicle fleet.

“The implication is that emissions on the roads could be changed quickly and dramatically by policy, and we have a tool to follow that relatively quickly. This is the way to know we are on track to meet our goals.”

For more information and to register for the Cities are the Key to the Climate Solution summit visit: https://www.strath.ac.uk/workwithus/globalenvironmentalmeasurementmonitoring/citiesarekeytotheclimatesolution/

ENDS

About Optica

Optica (formerly OSA) is dedicated to promoting the generation, application, archiving and dissemination of knowledge in optics and photonics worldwide. Founded in 1916, it is the leading organization for scientists, engineers, business professionals, students and others interested in the science of light. Optica’s renowned publications, meetings, online resources and in-person activities fuel discoveries, shape real-life applications and accelerate scientific, technical and educational achievement.

 

Further information

Stuart Forsyth

Corporate Communications Manager

University of Strathclyde

Stuart.m.forsyth@strath.ac.uk

0141 548 4373

Ranking of European cities with highest mortality due to lack of green space

Cities in Europe could prevent up to 43,000 deaths each year if they achieved the WHO recommendations on access to green space

Peer-Reviewed Publication

BARCELONA INSTITUTE FOR GLOBAL HEALTH (ISGLOBAL)

A team from the Barcelona Institute for Global Health (ISGlobal), a centre supported by the ”la Caixa” Foundation, has identified the European cities with the highest and lowest rates of mortality attributable to a lack of green space. The team analysed more than 1,000 cities in 31 European countries and concluded that up to 43,000 premature deaths could be prevented each year if these cities were to achieve the WHO recommendations regarding residential proximity to green space. The data were published in The Lancet Planetary Health and the city ranking is available at www.isglobalranking.org.

Green space is associated with a number of health benefits, including lower premature mortality, longer life expectancy, fewer mental health problems, less cardiovascular disease, better cognitive functioning in children and the elderly and healthier babies. It also helps to mitigate air pollution, heat and noise levels, contributes to CO2 sequestration and provides opportunities for physical exercise and social interaction.

Based on a review of the scientific evidence, the WHO recommends universal access to green space and sets that there should be a green space measuring at least 0.5 hectares at a linear distance of no more than 300 metres from every home. On the basis of these guidelines and data from previous studies, a team from ISGlobal’s Urban Planning, Environment and Health Initiative estimated the mortality attributable to a lack of green space in 978 cities and 49 metropolitan areas.  

To calculate the amount of green space in each city, the study used the Normalised Difference Vegetation Index (NDVI) as the main proxy. NDVI is an indicator that measures how green an area is. It takes into account all types of vegetation, from street trees to private gardens and it is calculated using satellite images. Since the type of vegetation differs among cities and regions and not all of them have the same kind of greenness, the team translated the WHO recommendation into a specific NDVI value for each city.

The team obtained data from 2015 on natural-cause mortality and green space levels for each city. Using a quantitative health impact assessment methodology and data from previous large meta-analyses of existing studies on the association between green space and mortality, they estimated the number of deaths from natural causes that could be prevented if each city were to comply with the WHO recommendation.

Over 60% of Population Has Insufficient Access to Green Space

The overall NDVI results showed that 62% of the population lives in areas with less green space than recommended. This lack of green space is associated with 42,968 deaths—2.3% of all deaths from natural causes—which could be prevented through compliance with the WHO recommendations.

“Our findings show that green space is very unevenly distributed across European cities, with mortality attributable to insufficient exposure to green space ranging from 0% to 5.5% of all natural deaths, depending on the city,” commented ISGlobal researcher Evelise Pereira, lead author of the study. “However, the uneven impact is not only between cities, but also between different areas within the cities, which puts some people at a disadvantage, depending on which city or neighbourhood they live in. Too often green spaces are not close to where people live, and people don’t get the health benefits”, she added.

The list of cities with the highest rates of mortality attributable to a lack of green space includes cities in Greece, Eastern Europe, the Baltic republics and Italy, as well as most of the continent’s capital cities. Specifically, the capital cities with the highest mortality rates were Athens, Brussels, Budapest, Copenhagen and Riga.
“This study provides an overview that shows that there is much work to be done in terms of re-greening cities and that the reduction of mortality could be even greater if we were to set more ambitious targets than the WHO recommendations,” remarked Mark Nieuwenhuijsen, Director of the Urban Planning, Environment and Health Initiative at ISGlobal and last author of the study.

“European cities should focus on reclaiming urban land for green space, introducing nature-based solutions such as green roofs and vertical gardens, and other measures such as rerouting traffic, digging up asphalt and replacing it with  green space, green corridors, street trees and pocket parks across the board. Our study also shows that it is important that green spaces are accessible and close to residences,” added Nieuwenhuijsen.

Percentage of green areas

The study included a second analysis using a different green space proxy: the percentage of green areas (%GA). Unlike the NDVI, this indicator measures the percentage of an area that is officially declared as green space and only takes into account public green areas. The estimations of the mortality burden associated to this proxy were based on less robust previous evidence and the results were not statistically significant. This second analysis showed a lower number of preventable deaths: 17,000 in total.

An important limitation of the study is that it did not consider the presence of blue spaces, such as rivers or beaches, whose possible health benefits, therefore, have not been estimated.

Full Rankings at www.isglobalranking.org

This study is the second in a series dedicated to measuring urban exposures in European cities. A ranking of cities by mortality attributable to air pollution was published in January 2021. The data and lists for both rankings are available at www.isglobalranking.org.

Top 5 Cities With Highest Burden of Mortality

The 5 cities with more than 100,000 inhabitants with the highest mortality burden due to low normalised difference vegetation index (NDVI) are as follows:

Rank	City	Country	Preventable deaths - NDVI	% of population below recommended levels
1	Trieste	Italy	145	74 %
2	Turin	Italy	546	92%
3	Blackpool	United Kingdom	144	73%
4	Gijón	Spain	138	71%
5	Brussels	Belgium	426	78%

Top 5 Cities With Lowest Burden of Mortality

The 5 cities with more than 100,000 inhabitants with the lowest mortality burden due to low normalised difference vegetation index (NDVI) are as follows:

Rank	City	Country	Preventable deaths - NDVI	% of population below recommended levels
1	Elche/Elx	Spain	4	20%
2	Telde	Spain	2	33%
3	Guimarães	Portugal	3	18%
4	Perugia	Italy	10	31%
5	Cartagena	Spain	10	51%

Reference

Pereira Barboza E, Cirach M, Khomenko S, Iungman S, Mueller N, Barrera-Gómez J, Rojas-Rueda D, Kondo M, Nieuwenhuijsen M, Green space and mortality in European cities: a health impact assessment study, Lancet Planet Health 2021; 5: e718–30. https://doi.org/10.1016/S2542-5196(21)00229-1.

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JOURNAL

The Lancet Planetary Health

DOI

10.1016/S2542-5196(21)00229-1 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Green space and mortality in European cities: a health impact assessment study

ARTICLE PUBLICATION DATE

7-Oct-2021

Nature-based activities can improve mood and reduce anxiety, new study shows

Peer-Reviewed Publication

UNIVERSITY OF YORK

Outdoor nature-based activities are effective for improving mental health in adults, including those with pre-existing mental health problems, a new study has found.

The research - led by the University of York - showed that taking part in outdoor, nature-based activities led to improved mood, less anxiety, and positive emotions.

The study found that activities lasting for 20 to 90 minutes, sustained for over the course of 8 to 12 weeks, have the most positive outcomes for improving mood and reducing anxiety.

Gardening and exercise were among the activities associated with mental health benefits. Engaging in conservation activities was also reported to make people feel better, as did ‘forest bathing’ (stopping in a forest to take in the atmosphere).

Nature-based interventions (NBIs) support people to engage with nature in a structured way to improve mental health.

As part of the study, researchers screened 14,321 NBI records and analysed 50 studies.

Lead author of the study, Dr Peter Coventry from the Department of Health Sciences, said: “We've known for some time that being in nature is good for health and wellbeing, but our study reinforces the growing evidence that doing things in nature is associated with large gains in mental health.

“While doing these activities on your own is effective, among the studies we reviewed it seems that doing them in groups led to greater gains in mental health.”

However, the study found there was less evidence that outdoor activities led to improved physical health. The research suggests that there needs to be more appropriate ways to measure the short and longer-term impact of nature-based activities on physical health.

The paper argues there is a need for substantial, sustained investment in community and place-based solutions such as nature-based interventions, which are likely to play important role in addressing a post-pandemic surge in demand for mental health support.

“One of the key ideas that might explain why nature-based activities are good for us is that  they help to connect us with nature in meaningful ways that go beyond passively viewing nature”, Dr Coventry adds.

The research forms part of the new ‘Environment and Health’ research theme, supported by the York Environmental Sustainability Institute (YESI). As part of the same theme, Dr Coventry and co-author Professor Piran White are now working with partners at the University of Central Lancashire to understand the health benefits of green social prescribing, in a study funded by the West Yorkshire and Harrogate Health and Care Partnership. 

Academics from the Department of Health Sciences, Department of Environment and Geography, York Environmental Sustainability Institute (YESI), Hull York Medical School and Stockholm Environment Institute at York contributed to the study.

###

Notes to editors

‘Nature-based outdoor activities for mental and physical health: Systematic review and meta-analysis’ is published in SSM - Population Health.

University of York academics from the Department of Health Sciences, Department of Environment and Geography, York Environmental Sustainability Institute, Stockholm Environment Institute contributed to the study, as well as researchers from the National Centre for Social Research, Hull York Medical School, Centre for Sustainable Healthcare, Oxford, and the Bradford Institute for Health Research.

The project is funded by the UKRI Closing the Gap Network and the NIHR Yorkshire and Humber ARC.

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JOURNAL

SSM - Population Health

DOI

10.1016/j.ssmph.2021.100934 

METHOD OF RESEARCH

Systematic review

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Nature-based outdoor activities for mental and physical health: Systematic review and meta-analysis

ARTICLE PUBLICATION DATE

1-Oct-2021

I AM OF COURSE A COFFEE COGNOSETI

Drinking our way to sustainability, one cup of coffee at a time

UMass Amherst researchers win NSF award to help re-envision the growing, selling and buying of coffee

Grant and Award Announcement

UNIVERSITY OF MASSACHUSETTS AMHERST

 

IMAGE: MARTIM MURILLO MEASURES WATER QUALITY OF RIO JACAGUA, ASSISTED BY FARLEM ESPANA. view more 

CREDIT: DAVID KING

AMHERST, Mass. – Coffee, that savior of the underslept, comes with enormous environmental and social costs, from the loss of forest habitats as woodlands are converted to crops, to the economic precarity of small-scale farmers whose livelihoods depend on the whims of international markets. Now, thanks to a National Science Foundation (NSF) grant of $979,720, Timothy Randhir, University of Massachusetts Amherst professor of environmental conservation, and David King, of the USDA Forest Service Northern Research Station, will embark upon a five-year effort to make Honduran coffee sustainable across environmental, economic and social fronts.

The research, which is part of a $3.4 million collaboration between UMass, Tulane University, the University of North Carolina Wilmington and Indiana University in Pennsylvania, centers around one question: “How can we make sustainable agriculture and forest conservation actually pay for itself?” asks King.

The answer lies in what Randhir has previously called “a convergence approach,” which is a way of tying the ultra-local—such as the work done by the small Honduran coffee planters with whom the team will work—to the global both socially, economically and environmentally. About 70% of the world’s coffee is produced on working landscapes at high altitudes on formerly forested land, primarily by small-scale, family farms in low- and middle-income countries. In many of these places, coffee production is the principal source of economic activity, yet conventional methods of coffee production combined with yield and market volatility have resulted in interlinked problems of environmental degradation, economic hardship and social crises.

Randhir and his colleagues have developed a suite of extremely sensitive models, collectively referred to as the Multi-Scale Ecosystem Framework, to study the many interactions between humans, the environment, and global economies so that they can understand which interventions will have what effect, both on a local and global scale.

The trick the team will perform is to figure out how environmentally sustainable coffee-growing practices, which leverage the ecosystem services provided by rainforest, conserved on coffee farms, can yield higher and more stable incomes for local Honduran growers while also supplying the world’s coffee drinkers with a steady quantity of high-quality liquid caffeine. A major part of this research involves installing and studying the effects that a new generation of solar-powered industrial coffee dryers, which will replace older, wood-fired dryers, has on environmental and economic sustainability.

It’s no understatement to say that Randhir and King’s project will touch upon just about everything. “I got into this through my interest in songbird conservation,” says King. Most of the warblers here in Massachusetts, that we think of as “ours,” spend their winters in the tropics, including in Honduras. “Unless their winter habitat is secured,” says King, “we can’t support what we think of as our native birds.” Human migration, too, is affected by the coffee industry, notes Randhir. “As small farmers’ livelihoods start to deteriorate, they migrate. If we can figure out how to help sustain the farms themselves, then farmers can remain in their homes.”

The team is partnering with the Mesoamerican Development Institute, in Lowell, Mass., and the Honduran coffee producing organization “Birding Coffee.” The work will take place in the Yoro region of Honduras. Honduras is the fifth largest coffee producer in the world and the largest coffee producer in Central America; coffee is the principal source of income for more than 100,000 Honduran families and provides employment for about a million people. The team will focus their efforts on the 12,000 square-kilometer Yoro Biological Corridor as a test-case to scale up their model, providing insights that the team anticipates will help inform global agricultural policy and practice.

“The biggest attraction of our research,” says Randhir, “is the way that the environmental, economic and social all come together toward a sustainable approach to agriculture.”

Unprecedented rise of heat and rainfall extremes in observational data

Peer-Reviewed Publication

POTSDAM INSTITUTE FOR CLIMATE IMPACT RESEARCH (PIK)

A 90-fold increase in the frequency of monthly heat extremes in the past ten years compared to 1951-1980 has been found by scientists in observation data. Their analysis reveals that so-called 3-sigma heat events, which deviate strongly from what is normal in a given region, now on average affect about 9 percent of all land area at any time. Record daily rainfall events also increased in a non-linear way – on average, 1 in 4 rainfall records in the last decade can be attributed to climate change. Already today, extreme events linked to human-caused climate change are at unprecedented levels, the scientists say, and they must be expected to increase further.

“For extreme extremes, what we call 4-sigma-events that have been virtually absent before, we even see a roughly 1000-fold increase compared to the reference period. They affected about 3 percent of global land area in 2011-20 in any month,” says lead-author Alexander Robinson from Complutense University of Madrid, Spain, and Potsdam Institute for Climate Impact Research, Germany. “This confirms previous findings, yet with ever-increasing numbers. We are seeing extremes now which are virtually impossible without the influence of global warming caused by greenhouse gas emissions from burning fossil fuels.” The term ‘sigma’ refers to what scientists call a standard deviation.

For example, 2020 brought prolonged heat waves to both Siberia and Australia, contributing to the emergence of devastating wildfires in both regions. Both events led to the declaration of a local state of emergency. Temperatures at life-threatening levels have hit parts of the US and Canada in 2021, reaching almost 50°C. Globally, the record-breaking heat extremes increased most in tropical regions, since these normally have a low variability of monthly temperatures. As temperatures continue to rise, however, record-breaking heat will also become much more common in mid- and high-latitude regions.

1 in 4 rainfall records is attributable to climate change

Daily rainfall records have also increased. Compared to what would have to be expected in a climate without global warming, the number of wet records increased by about 30 percent. This implies that 1 in 4 records is attributable to human-caused climate change. The physics background to this is the Clausius-Clapeyron relation, which states that air can hold 7 percent more moisture per degree Celsius of warming.

Importantly, already-dry regions such as western North America and South Africa have seen a reduction in rainfall records, while wet regions such as central and northern Europe have seen a strong increase. Generally, increasing rainfall extremes do not help to alleviate drought problems.

Small temperature increase, disproportionally big consequences

Comparing the new data with the already quite extreme previous decade of 2000-2010, the data show that the land area affected by heat extremes of the 3-sigma category roughly doubled. Those deviations which are so strong they have previously been essentially absent, the 4-sigma events, newly emerged in the observations. Rainfall records have increased a further 5 percentage points in the last decade. The seemingly small amount of warming in the past ten years, just 0.25°C, has thus pushed up climate extremes substantially.

“These data show that extremes are now far outside the historical experience. Extreme heat and extreme rainfall are increasing disproportionally,” says co-author Stefan Rahmstorf, from the Potsdam Institute for Climate Impact Research. “Our analysis confirms once again that for the impacts of global heating on us humans, every tenth of a degree matters.”

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JOURNAL

npj Climate and Atmospheric Science

DOI

10.1038/s41612-021-00202-w 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Increasing heat and rainfall extremes now far outside the historical climate

ARTICLE PUBLICATION DATE

5-Oct-2021

Cancer costs US more than $156 billion, with drugs a leading expense

Peer-Reviewed Publication

PENN STATE

HERSHEY, Pa. — Care for the 15 most prevalent types of cancer in the U.S. cost approximately $156.2 billion in 2018, according to a team of Penn State College of Medicine researchers. The team also found that medication was the biggest expense and that medication expense for breast, lung, lymphoma and colorectal cancers incurred the most costs.

In a study, the researchers examined a database that included statistics on cancer care for the 402,115 privately insured cancer patients younger than 65 in the U.S. The aim of the study was to gather this data to help understand how money is being spent on cancer care. This information traditionally has been difficult to track, mainly because the U.S. has different ways to cover healthcare costs, such as private insurance for people less than 65 years of age and Medicare for people aged 65 and over, according to Dr. Nicholas Zaorsky, assistant professor from the Departments of Radiation Oncology and Public Health Sciences at the College of Medicine and researcher at Penn State Cancer Institute.

“The public often hears that the U.S. spends an inordinate amount of money on health care, but no one has quantified exactly how big that number is and how is that number broken down for exactly what types of services,” said Zaorsky, who is an associate of the Institute for Computational and Data Sciences. “Cancer is a leading cause of death, actually overtaking heart disease as the leading cause of death in the U.S. over the past few years. But, it’s still unknown what we pay for in cancer care. As a team, we wanted to look at what private insurances are paying for each kind of cancer and for each type of service. We also wanted to look at what are the greatest number of services performed and how much does each one of those services cost.”

The researchers, who report their findings today (Oct. 6) in JAMA Network Open, said that the database included 38.4 million types of procedures — or common procedural terminology (CPT) codes — for the 15 cancers, which include breast, prostrate, colorectal, lung, lymphoma, melanoma, uterus, head and neck, bladder, kidney, thyroid, stomach, liver, pancreas and esophagus cancers. The cohort study used 2018 data — the most recent complete numbers available — from the IBM Watson Health MarketScan. The sample included 27.1 million privately insured individuals, including patients diagnosed with the most prevalent cancers.

Breast cancer incurred the most services, about 10.9 million services and procedures, followed by colorectal cancer, which had approximately 3.9 million services listed in the database. Breast cancer was also the most expensive type of cancer, costing a total of $3.4 billion, followed by lung cancer and colorectal cancer, which were both estimated to incur around $1.1 billion in costs.

According to the researchers, drug costs represent the most expensive category for treating cancer patients. About $4 billion were spent on drugs to treat cancer, which is double the $2 billion paid out for surgeries.

The study was not meant to assess whether the spending on drugs — or any of the services — was cost-effective, although Zaorsky said the study may help guide future research into the subject.

“It's hard to say like what is a reasonable price for a drug or service, but I think it’s fair to say that they make up the plurality of our health care spending in the U.S., then some would argue that this money may be better spent elsewhere in other services,” said Zaorsky. “These figures basically just show you how much the medical system spends on certain types of cancers versus another one. You might ask if these costs are justified. For example, pancreatic cancer is one of the deadliest cancers, but the total cost of care that we devote to pancreatic cancer is relatively low versus something like indolent prostate cancer.”

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For other future work, Zaorsky said that researchers might want to examine the cost of care at the time of diagnosis and track those costs over the years after diagnosis.

The team included Chachrit Khunsriraksakul, graduate student in bioinformatics and enomics; Samantha Acri, system analyst; Dajiang Liu, associate professor of medicine; Djibril Ba, research data management specialist, John Lin, a former medical student and now resident physician; Guodong Liu, associate professor of public health sciences, Joel Segel, associate professor of health policy and administration; Joseph Drabick, professor of medicine; Heath Mackley, radiation oncologist and Douglas Leslie, professor of public health sciences and psychiatry, all of Penn State College of Medicine. The authors declare no related conflicts of interest.

The Penn State Cancer Institute, the Penn State College of Medicine, the National Institutes of Health and the American Cancer Society supported the work.

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JOURNAL

JAMA Network Open

Early human activities impacted Earth’s atmosphere more than previously known

New study links an increase in black carbon in Antarctic ice cores to Māori burning practices in New Zealand more than 700 years ago

Peer-Reviewed Publication

DESERT RESEARCH INSTITUTE

 

IMAGE: FOUR ICE CORES FROM CONTINENTAL ANTARCTICA WERE DRILLED IN EAST ANTARCTICA, INCLUDING TWO AS PART OF THE NORWEGIAN-AMERICAN INTERNATIONAL POLAR YEAR ANTARCTIC SCIENTIFIC TRAVERSE. view more 

CREDIT: STEIN TRONSTAD

Reno, Nev. (Oct. 6, 2021) – Several years ago, while analyzing ice core samples from Antarctica’s James Ross Island, scientists Joe McConnell, Ph.D., and Nathan Chellman, Ph.D., from DRI, and Robert Mulvaney, Ph.D., from the British Antarctic Survey noticed something unusual: a substantial increase in levels of black carbon that began around the year 1300 and continued to the modern day.

Black carbon, commonly referred to as soot, is a light-absorbing particle that comes from combustion sources such as biomass burning (e.g. forest fires) and, more recently, fossil fuel combustion. Working in collaboration with an international team of scientists from the United Kingdom, Austria, Norway, Germany, Australia, Argentina, and the U.S., McConnell, Chellman, and Mulvaney set out to uncover the origins of the unexpected increase in black carbon captured in the Antarctic ice.

The team’s findings, which published this week in Nature, point to an unlikely source: ancient Māori land-burning practices in New Zealand, conducted at a scale that impacted the atmosphere across much of the Southern Hemisphere and dwarfed other preindustrial emissions in the region during the past 2,000 years.

“The idea that humans at this time in history caused such a significant change in atmospheric black carbon through their land clearing activities is quite surprising,” said McConnell, research professor of hydrology at DRI who designed and led the study. “We used to think that if you went back a few hundred years you’d be looking at a pristine, pre-industrial world, but it’s clear from this study that humans have been impacting the environment over the Southern Ocean and the Antarctica Peninsula for at least the last 700 years.”

CAPTION

The James Ross Island core drilled to bedrock in 2008 by the British Antarctic Survey provided an unprecedented record of soot deposition in the northern Antarctic Peninsula during the past 2000 years and revealed the surprising impacts of Māori burning in New Zealand starting in the late 13th century. Robert Mulvaney, Ph.D., pictured here led collection of the core.

CREDIT

Jack Triest

Tracing the black carbon to its source

To identify the source of the black carbon, the study team analyzed an array of six ice cores collected from James Ross Island and continental Antarctica using DRI’s unique continuous ice-core analytical system. The method used to analyze black carbon in ice was first developed in McConnell’s lab in 2007.

While the ice core from James Ross Island showed a notable increase in black carbon beginning around the year 1300, with levels tripling over the 700 years that followed and peaking during the 16th and 17th centuries, black carbon levels at sites in continental Antarctica during the same period of time stayed relatively stable.

Andreas Stohl, Ph.D., of the University of Vienna led atmospheric model simulations of the transport and deposition of black carbon around the Southern Hemisphere that supported the findings.

“From our models and the deposition pattern over Antarctica seen in the ice, it is clear that Patagonia, Tasmania, and New Zealand were the most likely points of origin of the increased black carbon emissions starting about 1300,” said Stohl.

After consulting paleofire records from each of the three regions, only one viable possibility remained: New Zealand, where charcoal records showed a major increase in fire activity beginning about the year 1300. This date also coincided with the estimated arrival, colonization, and subsequent burning of much of New Zealand’s forested areas by the Māori people.

This was a surprising conclusion, given New Zealand’s relatively small land area and the distance (nearly 4,500 miles), that smoke would have travelled to reach the ice core site on James Ross Island.

“Compared to natural burning in places like the Amazon, or Southern Africa, or Australia, you wouldn’t expect Māori burning in New Zealand to have a big impact, but it does over the Southern Ocean and the Antarctic Peninsula,” said Chellman, postdoctoral fellow at DRI. “Being able to use ice core records to show impacts on atmospheric chemistry that reached across the entire Southern Ocean, and being able to attribute that to the Māori arrival and settlement of New Zealand 700 years ago was really amazing.”

CAPTION

Black carbon deposition during the past 2000 years measured in ice cores from Dronning Maud Land in continental Antarctica and James Ross Island at the northern tip of the Antarctic Peninsula. Atmospheric modeling and local burning records indicate that the pronounced increase in deposition in the northern Antarctic Peninsula starting in the late 13th century was related to Māori settlement of New Zealand nearly 4000 miles away and their use of fire for land clearing and management. Inset shows locations of New Zealand and ice-core drilling sites in Antarctica.

CREDIT

DRI

Research impacts

The study findings are important for a number of reasons. First, the results have important implications for our understanding of Earth’s atmosphere and climate. Modern climate models rely on accurate information about past climate to make projections for the future, especially on emissions and concentrations of light-absorbing black carbon linked to Earth’s radiative balance. Although it is often assumed that human impacts during preindustrial times were negligible compared to background or natural burning, this study provides new evidence that emissions from human-related burning have impacted Earth’s atmosphere and possibly its climate far earlier, and at scales far larger, than previously imagined.

Second, fallout from biomass burning is rich in micronutrients such as iron. Phytoplankton growth in much of the Southern Ocean is nutrient-limited so the increased fallout from Māori burning probably resulted in centuries of enhanced phytoplankton growth in large areas of the Southern Hemisphere.

Third, the results refine what is known about the timing of the arrival of the Māori in New Zealand, one of the last habitable places on earth to be colonized by humans. Māori arrival dates based on radiocarbon dates vary from the 13th to 14th century, but the more precise dating made possible by the ice core records pinpoints the start of large scale burning by early Māori in New Zealand to 1297, with an uncertainty of 30 years.

“From this study and other previous work our team has done such as on 2,000-year old lead pollution in the Arctic from ancient Rome, it is clear that ice core records are very valuable for learning about past human impacts on the environment,” McConnell said. “Even the most remote parts of Earth were not necessarily pristine in preindustrial times.”

 

CAPTION

Drilling camp on James Ross Island, northern Antarctic Peninsula.

CREDIT

Jack Triest

Additional information:

The full study, Hemispheric black carbon increase after 13th C Māori arrival in New Zealand, is available from Nature: https://www.nature.com/articles/s41586-021-03858-9 

Study authors included Joseph R. McConnell (DRI), Nathan J. Chellman (DRI), Robert Mulvaney (British Antarctic Survey), Sabine Eckhardt (Norwegian Institute for Air Research), Andreas Stohl (University of Vienna), Gill Plunkett (Queen’s University Belfast), Sepp Kipfstuhl (Alfred Wegener Institut, Germany) , Johannes Freitag (Alfred Wegener Institut, Germany), Elisabeth Isaksson (Norwegian Polar Institute), Kelly E. Gleason (DRI/Portland State University), Sandra O. Brugger (DRI), David B. McWethy (Montana State University), Nerilie J. Abram (Australian National University), Pengfei Liu (Georgia Institute of Technology/Harvard University), and Alberto J. Aristarain (Instituto Antartico Argentino).

This study was made possible with funding from the National Science Foundation (0538416, 0968391, 1702830, 1832486, and 1925417), the DRI, and the Swiss National Science Foundation (P400P2_199285).  

To learn more about DRI’s Ice Core Laboratory, please visit: https://www.dri.edu/labs/trace-chemistry-laboratory/

CAPTION

Measuring the chemistry in a longitudinal sample of an ice core on DRI’s unique ice core analytical system.

CREDIT

Joe McConnell/DRI

The Desert Research Institute (DRI)  is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu. 

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JOURNAL

Nature

DOI

10.1038/s41586-021-03858-9 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Hemispheric black carbon increase after the 13th-century Māori arrival in New Zealand

ARTICLE PUBLICATION DATE

6-Oct-2021