Archive for the ‘Climate’ Category

New research finds plants release up to 30% more CO2 than previously thought

New research co-authored by a University of Canterbury scientist and academics from around the world suggests that plant respiration is a larger source of carbon emissions than previously thought. It warns that as the world warms, this may reduce the ability of Earth’s land surface to absorb emissions due to fossil fuel burning.

The findings, published in the journal Nature Communications this month was co-authored by Professor in Plant Physiological Ecology Matthew Turnbull, Head of UC’s School of Biological Sciences. They are based on the comprehensive GlobResp database, which comprises over 10,000 measurements of carbon dioxide plant respiration from many plant species and from across the globe.

Merging these data with existing computer models of global land carbon cycling shows plant respiration has been a potentially under-estimated source of carbon dioxide release to the atmosphere.

Across the world, carbon release by plant respiration may be around 30% higher than previously predicted. As mean global temperature increases, the researchers estimate that respiration will increase significantly.

Such increases may lower the future ability of global vegetation to offset carbon dioxide emissions caused by burning of fossil fuels.

People understand that plants take up carbon dioxide in photosynthesis, but less well known is that they also release it by respiration, Professor Turnbull says.

“In this international collaboration, including measurements in New Zealand forests, we find that respiration losses of carbon dioxide by plant respiration is 30% higher than previous estimates, and is expected to increase more than expected under global warming. This could have a major impact on the net amount of carbon dioxide that remains in the atmosphere, which we know is a major driver of the greenhouse effect.”

Plants both capture carbon dioxide and then release it by respiration. Changes to either of these processes in response to climate change have profound implications for how much ecosystems soak up carbon dioxide emissions from burning fossil fuels.

The lead author, Professor Chris Huntingford of the UK Centre for Ecology & Hydrology says for too long, plant respiration losses of carbon dioxide to the atmosphere have been “the Cinderella of ecosystem computer modelling”, with carbon dioxide gains via photosynthesis stealing the attention.

The new research addresses this, using extensive measurements of respiration to guide computer-based calculations of how carbon cycles through trees and plants.

This study has been the result of an especially close collaboration over several years between field scientists, those who build computer models of how the global land surface operates, and researchers assessing expected future climate change.

The study uses plant respiration data from over 100 remote sites around the world, from hot deserts in Australia, to the deciduous and boreal forests of North America and Europe, the arctic tundra in Alaska, and the tropical forests of South America, Asia, Africa and northern Australia.

Paper details: Huntingford, C., Atkin, O.K., Martinez-de la Torre, A., Mercado, L.M., Heskel, M.A., Harper, A.B., Bloomfield, K.J., O’Sullivan, O.S., Reich, P.B., Wythers, K.R., Butler, E.E., Chen, M., Griffin, K.L., Meir, P., Tjoelker, M.G., Turnbull, M.H., Sitch, S., Wiltshire, A. and Malhi, Y. (2017) “Implications of improved representations of plant respiration in a changing climate.”

Nature Communications. DOI: http://doi.org/10.1038/s41467-017-01774-z

 

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New method of assessing carbon footprints could identify “green” cattle

Implications of livestock farming on climate change should not be drawn from aggregate statistics, according to a study based on a new method of carbon footprinting for pasture-based cattle production systems that can assess the impacts of individual animals.

The new method, developed by a team from the University of Bristol and Rothamsted Research, records the environmental impact of each animal separately before calculating the overall burden of a farm.

Existing methods of carbon footprinting are primarily designed to quantify total greenhouse gas (GHG) emissions of a particular farm. They are unable to provide information on environmental performances of specific animals.

The ability to identify “green” cattle within a herd — cattle that produce lower emissions per kilogram of liveweight gain — promises more sustainable farming, they report in the study just published in the Journal of Cleaner Production.

The team applied both the new and old methods to field data collected at the North Wyke Farm Platform (NWFP), a Rothamsted state-of-the-art facility that supports three experimental farms over 63 hectares in Devon.

They demonstrated that the latter approach consistently underestimates levels of GHG emissions because it fails to consider sufficiently the impacts of poorly performing animals, which are known to produce disproportionally large amounts of methane through enteric fermentation.

“The research offers two important lessons that may seem paradoxical at first sight,” says Dr Taro Takahashi, Research Scientist at North Wyke and Senior Lecturer in Sustainable Livestock Systems and Food Security at Bristol Veterinary School, who led the research.

“Short-term, many carbon footprint estimates currently available are probably too low, which is clearly bad news for the industry. But long-term, this also means that mitigation of greenhouse gas emissions originating from ruminants could be easier than traditionally thought — if we are able to select the right animals through the right screening methods. And this is precisely what we are trying to achieve at North Wyke.”

The work also marked the first comprehensive evaluation of the three production systems at North Wyke.

“This study demonstrates the true value of primary data being collected by the NWFP team every day,” says Paul Harris, the facility’s project leader. “They can challenge our intuition and enhance our understanding of how we can make agriculture more sustainable.”

The new study comes as the debate about the role of livestock in sustainable global food production intensifies. In a report published this month, the Food Climate Research Network (FCRN) reiterated that livestock production is a net contributor to global warming regardless of the species and the rearing method.

“We agree with the FCRN report that ruminants cannot reverse climate change, even if they are grass-fed,” says Michael Lee, Head of North Wyke and Professor of Sustainable Livestock Systems at Bristol Veterinary School.

“However, as we discussed in our 2014 article in Nature, pasture-based livestock production systems have a multifaceted role in society — the point acknowledged, but not actively addressed, by the FCRN report.

“At Rothamsted, not only do we aim to advance knowledge on how to minimise negative impacts of agricultural production, as exemplified by the current paper, but also on how to optimise the positive contribution grazing livestock can bring to us as part of a well-designed food supply chain.”

Lee adds that such aspects include effective use of land unsuitable for growing crops, production of higher quality protein and more bioavailable micronutrients, improved animal welfare, prosperous rural communities and flood prevention. They all make up the bigger picture when looking for a sustainable future of food production.

Hayward kiwifruit in Bay of Plenty at risk from climate change

The most commonly grown variety of kiwifruit around Te Puke will not be commercially viable in the area by the end of the century, scientists predict.

A study into how climate change will affect production of the Hayward cultivar in the Bay of Plenty – the common bright green kiwifruit – has just been published in the New Zealand Journal of Crop and Horticultural Science.

The lead author, NIWA scientist Dr Andrew Tait,says it is globally recognised that the effects of climate change is an emerging risk to the economic value of fruit crops, especially those grown in warm, temperate regions such as kiwifruit.

“Our study shows that kiwifruit production around Te Puke steadily decreases over coming decades. It will be marginal by 2050 and most likely not viable by 2100 under all but the most stringent of global greenhouse gas emission options.”

The good news is that other parts of New Zealand will become suitable for kiwifruit production as temperatures rise.

About 90 per cent of New Zealand’s kiwifruit industry is based in the Bay of Plenty and more than half of that around Te Puke. Production is mostly the Hayward variety which is suited to the climate and soils of the area, including warm springs, mild summers and autumns and high sunshine hours.

Kiwifruit need sufficient “winter chilling” between May and July to produce high flower numbers in spring that result in fruit. High winter chilling, or colder sustained temperatures over this period, generally results in more flowers and an earlier flowering period.

Productivity significantly increased between 1980 and 2010 due to technology changes and the introduction of a chemical sprayed on the vines in late winter to improve the effects of winter chilling. New Zealand kiwifruit exports were worth $1558 million in the year ending June 2016 – up from $930 million the previous year.

But the use of the chemical, hydrogen cyanamide, may be restricted or banned in future.

“As air temperatures in New Zealand continue to rise, the potential for more years with marginal or poor winter chilling conditions steadily increases. This could put significant stress on the kiwifruit industry in the Te Puke area, particularly if hydrogen cyanamide is banned,” Dr Tait says.

“If this happens soon then there is an urgent need to consider the viability of Hayward kiwifruit production in other areas of the country, alongside genetic improvement.”

NIWA temperature data and high resolution mapping abilities showed areas further inland in the Bay of Plenty as well as Canterbury and Central Otago had potential as Hayward kiwifruit growing regions.

Through good planning, the New Zealand kiwifruit industry is likely to remain viable for many decades to come, Dr Tait says.

New scholarship to support greenhouse gas research

A new $400,000 scholarship programme to build global expertise on climate change, agriculture and food security,  announced at the Global Research Alliance on Agricultural Greenhouse Gases (GRA) Council meeting in Tsukuba, Japan, will boost New Zealand’s contribution to agricultural greenhouse gas research.

The scholarship is a joint initiative of the GRA and the Consultative Group on International Agricultural Research.

It builds on the $20 million a year New Zealand already invests in agricultural emissions.

This funding support will enable up to 40 recipients to be hosted in research centres of GRA partners and member countries over the next three years.

New Zealand has been a long-standing donor of the CGIAR, most recently committing a further $11 million over two years to its network of research institutes around the world.

For more information see www.globalresearchalliance.org.

 

 

 

Veteran science journalist laments public rejection of climate change evidence

A 98-year-old US science journalist, who has finally decided to retire, says a generation of Americans are suffering from a “major disability in what they can think about and understand”.

This  was one reason why so many people refused to recognise climate change was real, David Perlman told the website of the Poynter Institute, which trains the media.

For the majority of his career, he has covered scientific progress in the 20th century and beyond, writing thousands of articles about everything from the beginning of the space age to the computer age.

Perlman, a journalist at The San Francisco Chronicle,  described cuts in science coverage by newspapers as “absolutely obscene”.

 “Newspapers, whether online or in print, are a major factor in the ongoing education and awareness of the public, and specifically of a younger generation,” he said.

“And whether it’s online or in print, the idea of failing to cover advances in science … it creates a generation with a major disability in what they can think about and understand.”

Perlman has not only won awards but had them named after him, The Independent says (HERE) in a report on his remarks.

The lack of critical thinking that dismays him was being demonstrated in the US public’s reaction to scientific evidence that the world is getting warmer because of greenhouse gas emissions, largely caused by fossil fuels.

“A perfect example of that [lack of understanding of science] is the controversy over climate change, global warming and all that that implies,” Mr Perlman said.

“The failure of people to understand that this is real science, and it’s just as scientifically valid as an issue today as is the fact that we’re going to have an eclipse of the sun on August 21. That’s not a theory — that’s going to happen.

“And the climate is going to change more, and more and more.

“The resistance to an understanding of that I can understand … which is largely generated by people whose economic interests are threatened by the fact that what’s causing the changing climate is, in fact, the increasing emissions of greenhouse gases.”

A recent poll by YouGov found 57 per cent of Americans thought that a combination of human activity and natural causes were causing global warming.

Nasa and other scientific bodies, however, say greenhouse gas emissions have caused the vast majority of recent warming with the world experiencing three successive, record-breaking hottest years. The natural El Nino weather cycle has had a relatively minor effect.

Mr Perlman said once there had been 50 to 75 pages in newspapers devoted to science across the US but now “there’s The New York Times on Tuesday” with only a few others having anything similar.

He said newspapers have abdicated their responsibility by diminishing the amount of science coverage.

Time to take a historic step for climate change, says Jan Wright

The Parliamentary Commissioner for the Environment, Dr Jan Wright, has challenged MPs of all parties to come together to tackle climate change.

 “Climate change is the ultimate intergenerational issue,” said Dr Wright.

“It’s a huge challenge. And not just for the current Government, but also for the Governments that succeed them into the future, be they blue, red, green, or any other colour,”

In a new report, the Commissioner acknowledges that the Government has made progress since the Paris agreement. And the cross-party working group on climate change has been a welcome development.

But she says it’s now time to take the next step.

 “There is an opportunity here for the next Parliament to build on recent developments and take a historic step forward that will be credited for generations to come,” said Dr Wright.

Dr Wright has recommended a new Act, similar to the UK Climate Change Act. This is a law that was passed with overwhelming cross-party support in the House of Commons in 2008.

Several other countries have since passed similar legislation, including Denmark, Finland, France, Ireland, Mexico, Norway, Scotland, Sweden, and Switzerland.

A similar law in New Zealand would put emissions targets into law, and require the setting of carbon budgets that would act as stepping stones towards the targets. It would also establish a high-powered independent expert group that would crunch the numbers and provide objective advice.

 “There has been a lot of debate around what our targets should be,” said Dr Wright. “But I’m much more interested in how we are actually going to achieve them.”

The Commissioner says underlining her recommendations is the need for a long-term approach to climate change.

“When it comes to climate change, we need to get used to looking decades ahead,” said Dr Wright. “The world is going to be a very different place in the future.”

The report is subtitled Climate change, progress, and predictability. Dr Wright says businesses and investors are crying out for some predictability in New Zealand’s response to climate change.

 “Many businesses are keen to take advantage of the opportunities of moving to a low-carbon economy, but they need more predictability before they invest.”

The Commissioner’s report, Stepping stones to Paris and beyond: Climate change, progress, and predictability, is available HERE.

A set of frequently asked questions is available HERE. 

 

Hamilton student goes to court to battle NZ Govt over climate change policies

A law student from Hamilton is challenging the Government in the High Court over what she claims is a “failure” to properly address climate change.

According to Sarah Thomson, 26, New Zealand’s targets under the Paris Climate Agreement are “unambitious” and fail to reflect scientific consensus on climate change.

The case, the first of its kind in New Zealand, will be heard over three days from today in the Wellington High Court.

Thomson says she has been inspired by climate change litigation around the globe, including the 900 Dutch citizens who filed a case the Dutch Government and a case in the US where 21 young people are suing the Federal Government.

She says she has the backing of several world-renowned climate change experts, including former NASA researcher James Hansen, who is giving evidence in the case.

Intergovernmental Panel on Climate Change author and Victoria University of Wellington Professor James Renwick is also giving evidence.

The lawsuit will ask the Minister for Climate Change Issues to justify the way in which New Zealand’s climate targets have been set.