Australia’s summers are getting increasingly brutal—but they’re also inspiring new climate science that could lead to better predictions and carbon accounting.
Five years ago, a study in the Journal of Climate by Australian and U.K. scientists predicted climate change would deliver more intense summers to Australia. That study, led by Tim Cowan of the Commonwealth Scientific and Industrial Research Organization (CSIRO), forecast that by the end of this century, the northern tropical reaches of Australia will experience longer and more frequent heat waves, while the hottest parts of southern Australia will see increases in maximum temperature of around 5.4 degrees Fahrenheit.
That prediction is now proving prescient.
The 2018-19 Southern Hemisphere summer has delivered new record temperatures in several parts of the continent, including the hottest temperature ever recorded for a provincial capital as thermometers topped 116 degrees Fahrenheit in Adelaide last week.
To accompany the hot start to 2019, Australian scientists have published a slew of new climate change-related studies. They say their research can improve understanding of the impacts of climate change, as well as help other nations find better means of keeping tabs on carbon emissions, and hopefully mitigating against them. Teams at the Australian National University, the University of Melbourne and Griffith University led the studies.
Getting ahead of the problems Australia will face from hotter summers may be possible thanks to new technology and techniques, as outlined in a paper issued this week by ANU scientists.
Writing in Nature Communications, Siyuan Tian and her team say they’ve developed a means to forecast droughts up to five months in advance. Rather than looking up to the weather, their approach focuses on looking downward via satellite measurements of groundwater changes.
“Our paper assimilated multiple satellite observations to the hydrological model for soil water balance estimation,” Tian said. “Our method and results highlight the importance to understand the vegetation response to soil water availability and the potential of using this information in the forecasting of drought impacts.”
The research used data from the now-decommissioned Gravity Recovery and Climate Experiment (GRACE) satellites, along with other sources of remote sensing data. The authors say tracking changes in groundwater and vegetation allowed them to forecast both regional drought conditions and wildfire risks. Their methodology can be applied to anywhere on Earth.
The data gathered are only good for shorter-term analysis, though, and aren’t suitable for making longer-term climate change impact predictions, Tian cautioned.
“Satellite water remote sensing provides us the best knowledge on the current status of water availability and the great forecast potential, but the data is not long enough for the study of global warming,” she said.
Taking stock of carbon
A separate ANU study in Environmental Science & Policy aims to help other nations improve their carbon counting methodologies.
ANU scientist Heather Keith said current methods rely on too little information about existing stocks of carbon in forests, or the length of time that carbon storage actually occurs. Her research is aimed at filling this gap.
“Current carbon accounting rules for the Kyoto Protocol and Australian national reporting do not include natural ecosystems where there are no human activities that affect GHG emissions,” Keith explained. “This means that the carbon stored in these ecosystems is not accounted, and hence not valued.”
In other words, she said, “if production forests were not harvested and allowed to continue growing, this carbon sequestration is currently not accounted for, reported or valued.” Finding this value, the research concludes, yields better information on the different benefits derived from either harvesting an ecosystem or letting nature take its course.
Keith and her team demonstrated the approach by estimating the economic value of allowing a southeast Australia forest to grow and spread versus logging it.
They concluded that the value derived from the forest outside Melbourne at current carbon market prices is approximately equal to that to be had by logging. But the value of protecting it and allowing it to expand proved much greater when other services that the forest provides were also taken into account, in particular “improving water yield, tourism, recreation and biodiversity conservation.”
“Carbon trading schemes, such as the Australian government’s Emissions Reduction Fund or voluntary markets, could pay for these mitigation activities of (i) forest protection to avoid harvesting and (ii) allowing on-going regeneration without further harvesting, in the same way that other land-based activities are funded, such as afforestation and avoided vegetation clearing,” Keith said in an email.
A parallel study published in the same journal seeks to improve estimates of greenhouse gas emissions caused by forest fires.
Led by Liubov Volkova at the University of Melbourne, that study explains the steps to achieve the “Tier 2” accounting approach outlined in 2006 by the U.N. Intergovernmental Panel on Climate Change.
Volkova said her team’s study could improve developing nations’ chances of receiving appropriate compensation for their REDD+ activities, or things they do to reduce emissions from deforestation and land degradation.
“The main idea of our study was to improve accuracy of emission estimates from forest fires and inspire the developing countries to take a stepwise approach in the reporting,” Volkova explained. “Countries, seeking to receive results based payments from REDD+, are required to submit and defend ... their emission estimates. Accuracy of estimates is the biggest problem.”
By following the technical process Volkova’s team outlined, developing nations may see gains from their measures to reduce or prevent forest fires.
“Once a country has realistic emission estimates and identifies major categories of emissions, then steps for emission reduction can be developed, such as early dry season burning to reduce intensity of late dry season fires and tree mortality and increase patchiness of the burns, etc.,” Volkova said.
The scientists behind these new studies acknowledge that their findings are from data gathered and research conducted from past years and months—and don’t include the impact of the ongoing heat wave.
The Cowan paper, originally published in April 2014, argued that Australian summers will gradually get worse as high concentrations of carbon dioxide in the atmosphere take their toll. The authors predicted dire consequences for human health and parts of Australian agriculture as the summer temperatures continue to rise. Winters are also expected to get hotter.
“Model consensus suggests that future winter warm spells will increase in frequency and duration at a greater rate than summer heat waves,” the Cowan paper said.
It warned: “The hottest events will become increasingly hotter for both seasons by century’s end.”
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.