Update on national soil carbon benchmarking and monitoring

Under the United Nations Framework Convention on Climate Change and the Paris Agreement, New Zealand every year must report its national human-produced (anthropogenic) greenhouse gas (GHG) emissions and removals, including changes in soil organic carbon (SOC) stocks.

With average soil carbon stocks in New Zealand’s agricultural soils estimated at about 100 tonnes per hectare in the top 30 cm, any change in soil carbon could make a significant contribution to carbon footprints at national, industry and farm scales.

Soil carbon monitoring sites across five land-use classes.

National-scale changes of SOC stocks in mineral soils are currently predicted based on transitions of land use (for example, forest to pasture) using a statistical model calibrated with historical data.

The model assumes that SOC doesn’t change if there isn’t a change in land use (for example, if an area remains in long-term pasture). Continue reading

Forestry and carbon credits: farm leaders press for clear plan to address climate impacts

The Government announced early in March that new proposals to better manage carbon farming could result in future permanent plantings of exotic forests – such as radiata pine – being excluded from the Emissions Trading Scheme (ETS).

Forestry Minister Stuart Nash and Climate Change Minister James Shaw at that time released a public discussion document to prompt feedback on ideas to better manage afforestation.

The Government wanted to encourage afforestation to help meet the country’s climate change targets, offset carbon emissions, and help farmers, landowners and investors diversify their income streams, Stuart Nash said.

From 2023, under current rules, a new permanent forest category of the ETS would allow both exotic and indigenous forests to be registered in the ETS and earn New Zealand Units (NZU).

Under the new proposal, exotic species would be excluded from the permanent forest category. Continue reading

Infected pines starve and disease-causing fungi thrive as the globe warms

The high heat and low water conditions produced by global warming weaken pine trees’ resistance to disease by hindering their ability to mount an effective defense at the same time that pathogenic fungi in their tissues become more aggressive, new research suggests.

The study is the first to simultaneously examine metabolic gene expression in both host trees and the pathogens attacking them under normal and climate-change conditions. The findings help explain the mechanisms behind what has become a well-known fact: The warming world makes trees more susceptible to disease.

The study was conducted on Austrian pines, which are native to southern Europe and used ornamentally in the United States. Researchers tested climate change conditions’ effects on the trees after infection by two related fungi that have killed large swaths of these pines over time. Continue reading

Climate change the issue on which Australians do not want both sides of the argument: new research

Researchers have found Australians do not want both sides of the argument when climate change is at issue. They also found (encouragingly) that the most popular sources of climate change news are scientists, experts and academics (50%).  The findings are reported today in The Conversation in an article by Sora Park, Associate Dean of Research in the Faculty of Arts & Design, Kerry McCallum, Professor of Communication and Media Studies, Director, News and Media Research Centre, and Kieran McGuinness post-doctoral felllow, News & Media Research Centre, at the University of Canberra  They write:

Should journalists always treat an issue even-handedly? Our research reveals that when it comes to climate change, many Australians would prefer they didn’t. For general news, people want news outlets to reflect a range of views so they can make up their own mind about an issue. However, when it comes to news about climate change, four in ten say news outlets should pick a side.

There is a divide driven by political orientation on how people think news outlets should be reporting on climate change. More than half (51%) of those who identify as left-wing and 42% of those who identify as centre of politics say news outlets should take a clear position. In contrast, only 24% of right-leaning audiences say so. Continue reading

B+LNZ says it’s time for farmers to know their GHG numbers

Farmers from Southland to the Far North are taking part in workshops to know their greenhouse gas (GHG) numbers and create action plans. Meat processors are teaming up with Beef and Lamb NZ to deliver many of these workshops.

Under He Waka Eke Noa, the primary sector’s climate change commitment to measure, manage and reduce GHG emissions, farmers will need to know their farm’s annual GHG numbers by December.

By January 2025, they will need to have a written plan in place for measuring and managing their emissions.

The B+LNZ workshops are being hosted in partnership with Silver Fern Farms and Greenlea Premier Meats. Continue reading

Govt’s seeks feedback on blueprint for adapting to a warmer world

New Zealanders can have their say from today on a proposed National Adaptation Plan to help communities across the country adapt to the unavoidable impacts of climate change.

Reforming resource management, bringing in laws to support managed retreat, and updating how the government handles emergencies are among the top priorities in the draft plan.

The plan aims at bringing down emissions and helping prevent the worst effects of climate change, but must also support communities already being hit by more extreme and more frequent weather events, Climate Change Minister James Shaw said.

Central Government does not bear all the costs under the proposal.  The consultation asks how best to share risks and costs between property and asset owners, insurers, banks and local government as well.

It also asks for views on managed retreat and flood insurance, to ensure a joined-up approach to climate change adaptation. Continue reading

Agriculture and climate change combined can halve insect populations

Interplay between historical climate warming and intensive agricultural land use is associated with a reduction of almost 50% in insect abundance, reports a paper in Nature.

Climate change and land-use change are known to affect insect biodiversity, and these factors can act synergistically; for example, removing natural habitats to make agricultural land can alter the microclimate and increase temperature extremes. But the effect of interactions between these factors and insect biodiversity is less well understood than for other animal species.

To address this gap in knowledge, Charlotte Outhwaite, Peter McCann and Tim Newbold combined data on temperature changes and land-use changes with data on insect biodiversity in more than 6,000 different locations around the world, with the data spanning a 20-year period. Continue reading

Relocating farmland could turn back clock 20 years on carbon emissions, scientists say

Scientists have produced a map showing where the world’s major food crops should be grown to maximise yield and minimise environmental impact. This would capture large amounts of carbon, increase biodiversity, and cut agricultural use of freshwater to zero.

The reimagined world map of agriculture includes large new farming areas for many major crops around the cornbelt in the mid-western US, and below the Sahara desert. Huge areas of farmland in Europe and India would be restored to natural habitat.

The redesign — assuming high-input, mechanised farming — would cut the carbon impact of global croplands by 71%, by allowing land to revert to its natural, forested state. This is the equivalent of capturing twenty years’ worth of our current net CO2 emissions. Trees capture carbon as they grow, and also enable more carbon to be captured by the soil than when crops are grown in it. Continue reading

Global warming is amplifying the water cycle much faster than expected

The global water cycle – the constant movement of freshwater between the clouds, land and the ocean – plays an important role in our daily lives. This delicate system transports water from the ocean to the land, helping to make our environment habitable and soil fertile.

But rising global temperatures have been making this system more extreme: water is moving away from dry regions towards wet regions, causing droughts to worsen in parts of the globe while intensifying rainfall events and flooding in others.

In other words, wet areas are getting wetter, and dry areas are getting drier.

Until now, changes to the cycle have been difficult to directly observe, with around 80% of global rainfall and evaporation happening over the ocean.

But a new University of New South Wales-led study, published this week in Nature, has used changing patterns of salt in the ocean to estimate how much ocean freshwater has moved from the equator to the poles since 1970. The findings show that between two and four times more freshwater has moved than climate models anticipated – giving us insights about how the global water cycle is amplifying as a whole. Continue reading

Wheat shifts its pest defenses under future climate conditions

Higher CO2 levels under future climate conditions may cause wheat to shift its pest defence strategy, according to Australian research.

When the researchers grew wheat under higher levels of CO2, they found it switched from silicon-based defences (these reduced by 19%) to carbon-based defences.

The good news is that the plants were still able to resist the cotton bollworm, a global wheat pest.

The switch wasn’t enough to change resistance to this pest, but it may impact resistance to others, so applying silicon fertilisers may help maintain pest resistance in future climates, the authors say.

Just three grass crops – wheat, maize and rice – provide 42% of human calories. Continue reading