A new global accord has been set up to align the swelling cryptocurrency market with the ambitions of the Paris Agreement by ensuring that blockchain and energy-intensive currency mining systems are powered by renewables and reach net-zero emissions by 2040.
Big fan of podcasts? You’re not alone. In 2020, more than 100 million Americans listened to at least one podcast each month.
Podcasts can provide access to on-the-go environmental education. But with millions of episodes available to download, it can be challenging to know where to start if you are new to the platform.
Below, we’ve curated a list of thought-provoking, informative, and entertaining environmental podcasts, just in time for Earth Day 2021. These podcasts will transport you to the outdoors and introduce you to fascinating stories from the world of conservation.
Trees are the Earth’s lungs – it’s well understood they drawdown and lock up vast amounts of carbon dioxide from the atmosphere. But emerging research is showing trees can also emit methane, and it’s currently unknown just how much.
This could be a major problem, given methane is a greenhouse gas about 45 times more potent than carbon dioxide at warming our planet.
However, in a world-first discovery published in Nature Communications, we found unique methane-eating communities of bacteria living within the bark of a common Australian tree species: paperbark (Melaleuca quinquenervia). These microbial communities were abundant, thriving, and mitigated about one third of the substantial methane emissions from paperbark that would have otherwise ended up in the atmosphere.
Because research on tree methane (“treethane”) is still in its relative infancy, there are many questions that need to be resolved. Our discovery helps fill these critical gaps, and will change the way we view the role of trees within the global methane cycle.
Wait, trees emit methane?
Yes, you read that right! Methane gas within cottonwood trees was first reported in 1907, but has been largely overlooked for almost a century.
In some cases, treethane emissions are significant. For example, the tropical Amazon basin is the world largest natural source of methane. Trees account for around 50% of its methane emissions.
Likewise, research from 2020 found low-lying subtropical Melaleuca forests in Australia emit methane at similar rates to trees in the Amazon.
Dead trees can emit methane, too. At the site of a catastrophic climate-related mangrove forest dieback in the Gulf of Carpentaria, dead mangrove trees were discovered to emit eight times more methane than living ones. This poses new questions for how climate change may induce positive feedbacks, triggering potent greenhouse gas release from dead and dying trees.
Treethane emissions most likely account for some of the large uncertainties within the most recent global methane budget, which tries to determine where all the methane in the atmosphere comes from. But we’re still a long way from refining an answer to this question. Currently, trees are not yet included as a distinct emissions category.
So where exactly is the treethane coming from?
Within wetland forests, scientists assumed most treethane emissions originate from the underlying soils. The methane is transported upwards via the tree roots and stems, then through to the atmosphere via their bark.
We confirmed, in other recent research, that wetland soils were indeed the source of methane emissions in lowland forest trees. But this wasn’t always the case.
Some lowland forest trees such as cottonwood can emit flammable methane directly from their stems, which is likely produced by microbes living within the moist trees themselves. Dry upland forest trees are also emerging as methane emitters too — albeit at much lower rates.
Discovering methane-eating bacteria
For our latest research, we used microbiological extraction techniques to sample the diverse microbial communities that live within trees.
We discovered the bark of paperbark trees provide a unique home for methane-oxidizing bacteria — bacteria that “consumes” methane and turns it into carbon dioxide, a far less potent greenhouse gas.
Remarkably, these bacteria made up to 25% of total microbial communities living in the bark, and were consuming around 36% of the tree’s methane. It appears these microbes make an easy living in the dark, moist and methane-rich environments.
This discovery will revolutionise the way in which we view methane emitting trees and the novel microbes living within them.
Only through understanding why, how, which, when and where trees emit the most methane, may we more effectively plant forests that effectively draw down carbon dioxide while avoiding unwanted methane emissions.
Our discovery that bark-dwelling microbes can mitigate substantial treethane emissions complicates this equation, but provides some reassurance that microbiomes have evolved within trees to consume methane as well.
Future work will undoubtedly look further afield, exploring the microbial communities of other methane-emitting forests.
A trillion trees to combat climate change
We must be clear: trees are in no way shape or form bad for our climate and provide a swath of other priceless ecosystem benefits. And the amount of methane emitted from trees is generally dwarfed by the amount of carbon dioxide they will take in over their lifetime.
However, there are currently 3.04 trillion trees on Earth. With both upland and lowland forests capable of emitting methane, mere trace amounts of methane on a global scale may amount to a substantial methane source.
As we now have a global movement aiming to reforest large swaths of the Earth with 1 trillion trees, knowledge surrounding methane emitting trees is critical.
Dr. Esther Ngumbi began her life’s work as a child alongside a river in rural Kenya.
At just seven years old, Ngumbi wanted a hand at farming, so her parents gave her a small strip of land near the river that she could plant cabbage on. Though her parents were both passionate educators, their incomes from teaching alone could not sustain her immediate and extended family, so her parents supplemented their earnings through farming.
Ngumbi would tend to her cabbages each day and often help her parents farm, watching as the crops sprouted from the soil, hopeful and green. But then, “halfway through the season, insects would come and go through our crops, and sometimes what insects hadn’t taken away, drought would,” says Ngumbi, now an assistant professor of entomology at the University of Illinois at Urbana-Champaign. “I would watch this as a kid. A lot of our hard work — waking up in the morning and going to the farm — would be eaten by insects.”
The agricultural problems facing her family were not unique but were endemic to other farmers in her community, and she realized this early on. Even from a young age, Ngumbi wanted to know what the insects were and how farmers could control them. She wanted a career that could help her community grow plentiful food amid challenging circumstances and a changing climate.
The International Monetary Fund (IMF) has launched a new Climate Change Indicators Dashboard—an international statistical initiative to address the growing need for data in macroeconomic and financial policy analysis to facilitate climate change mitigation and adaptation.
The Dashboard is a single platform that brings together experimental climate change indicators that allows comparison across countries. The indicators have been developed in cooperation with international organizations and other agencies including the Organisation for Economic Co-operation and Development (OECD), the World Bank Group (WBG), the United Nations (UN), the European Commission, the European Statistical Office (Eurostat), the Food and Agriculture Organization (FAO), the International Energy Agency (IEA) and the National Oceanic and Atmospheric Administration (NOAA).
The indicators presented are the result of estimates from IMF staff and other publicly available data sources.
The selection and development of the experimental indicators are driven by the IMF’s need for member countries surveillance, monitoring, policy making, and research. The Dashboard covers greenhouse gas emissions from economic activity, trade in environmental goods, green finance, government policies, and physical and transition risks.
“To develop the right measures to tackle climate change, governments need robust and comparable data. The new IMF Dashboard will help fill data gaps, so policymakers can undertake the macroeconomic and financial analysis that underpins effective policies,” IMF Managing Director Kristalina Georgieva said.
Near America’s largest coal-fired power plant, toxins are showing up in drinking water and people have fallen ill. Thousands of pages of internal documents show how one giant energy company plans to avoid the cleanup costs.
The Palmolive Ultra brand of dish soap is now using a 100% post-consumer PET bottle in North America.
Global brand owner Colgate-Palmolive announced the relaunch of one of its flagship products in a post-consumer resin (PCR) bottle, noting the change will lead to the recycling of an additional 5,200 tons of PET a year in North America.