Welcome to Carbon Brief’s Cropped. 
We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.

Key developments

Wildfires resurfaced

PANTANAL FIRES: Climate change made the wildfires that scorched the Pantanal wetlands earlier this summer 40% more intense, according to a new rapid attribution study covered by Carbon Brief. Around 2,500 fires occurred in Brazil’s Pantanal wetlands in June 2024. The World Weather Attribution service found that “the month was the hottest, driest and windiest year in the 45-year record”, creating conditions that were highly conducive to wildfires. Separately, Reuters reported on a new study that found that fires, logging and “other forms of human-caused degradation, along with natural disturbances to the Amazon ecosystem, are releasing more climate-warming CO2 than clear-cut deforestation”. 

EXTENDED IMPACT: In North America, 90 large fires burned nearly 4.5m acres across the US during the first days of August, the New York Times reported. The “devastating wildfires” spread ash and smoke “over large swathes of the continent…destroyed homes and charred through thousands of acres of farms and forests”, the outlet added. Particularly dry, hot weather affected the western US and caused four wildfires across Colorado, leaving one person dead and forcing hundreds of people to evacuate, according to the Washington Post. 

BEYOND AMERICAN CONTINENT: On the other side of the ocean, wildfires swept Athens, where thousands of residents were evacuated as fires crossed into suburbs and flames rose up to 25 metres, BBC News reported. According to the outlet, June and July were “the hottest on record” for the European country, while Greece’s civil protection minister has “warned that extremely dangerous weather would continue”. Meanwhile, Algeria’s north-eastern Kabylie region has experienced blazes since last Friday, Agence France-Presse reported. The newswire added that homes, olive groves, hen coops and beehives were engulfed by flames. Most of the wildfires are now under control, a civil defence official said.

Offsets up in smoke

UP IN SMOKE: The Park fire – one of the “largest wildfires in California’s history” and is still blazing – destroyed around 45,000 acres of trees enrolled in the state’s carbon-offsetting programme, the Financial Times reported. According to analysis by the not-for-profit research firm Carbon Plan, cited in the story, buyers of credits included oil refining, power and lumber companies. The story also pointed to an unsold “buffer pool” of credits meant to replace losses to “credited trees” from wildfires, drought or pests. California authorities told the FT that the buffer was “quite sound”. But Carbon Plan scientist Dr Grayson Badgley said that the pool needed updating to “reflect the realities of fire risk” and that the state “should stop approving carbon credit projects in risky wildfire regions”. 

STOLEN CREDIT: Brazil’s environment minister, Marina Silva, warned international buyers of carbon credits to be “vigilant” after police uncovered “allegedly fraudulent emissions-offset schemes on stolen land in the Amazon”, the Financial Times wrote. Silva said the issue was a “serious problem” and “could damage the credibility [and] integrity of this mechanism”, the story added. Separately, Bloomberg reported that a key oversight body is set to review carbon offsets generated from forestry projects “in the coming months”, after it found methods to assess renewable energy credits to be “insufficiently rigorous”.

FOREST THINNING: Meanwhile, scientists writing in the Conversation cautioned against the Australian forest industry’s plans “to remove trees from native forests, potentially including national parks, and claim carbon credits in the process”. They pointed to Forestry Australia’s “problematic proposal” that “purports to reduce environmental impacts, but still produce wood products”. It does so through a method known as “adaptive harvesting”, which involves forest thinning, or practices such as delaying logging until trees are older. The group’s acting president, William Jackson, responded to the piece, saying that forest thinning would be “conducted for ecological reasons, cultural values or fire management or other reasons” and that he “disagrees with the view that thinning makes forests more fire prone”.

Spotlight

Joshua trees are flowering more frequently due to climate change

This week, Carbon Brief explores a new study, published in Ecology Letters, looking at the impacts of climate change on the Joshua tree, a type of yucca plant that is native to California and other parts of the south-western US.

Climate change is causing Joshua trees – the iconic plant that dots the landscape of the south-western US – to flower more frequently, a new study has found.

Despite the plant’s importance as a keystone species in the Mojave Desert and other parts of the south-west, many studies of climate impacts on Joshua trees lack nuance – in part due to the resources needed to collect field data.

Using a machine-learning model trained on crowdsourced images from the biodiversity platform iNaturalist, researchers were able to examine the impacts of climate change on the trees since 1900.

The lead author of the study told Carbon Brief that “there’s a lot of potential” to use the team’s newly developed methods to study the impacts of climate change on other flora.

Beyond binary

Much of the existing work looking at climate change impacts on Joshua trees is based on so-called “distribution models”, Prof Jeremy Yoder, an evolutionary biologist at California State University, Northridge, told Carbon Brief. 

These models are based on identifying the climatic factors that are closely associated with the presence or absence of a particular species. Then, he explained, researchers can “take a future climate projection and ask where conditions will look like places where we know Joshua trees are today”.

In the new study, instead of simply looking at the distribution of the species, the researchers modelled the flowering of the trees – using specific weather data to draw connections between a flowering year and the climatic conditions leading up to it.

Using this model, they were then able to “hindcast” previous instances of Joshua tree flowering. They matched up their predicted flowering with historical botanical collections, field notes and even newspaper reports and found that they “line up pretty well”. 

By taking the hindcast as a whole, the team could then explore how climate change has affected Joshua tree flowering over the past century and a quarter. Yoder told Carbon Brief:

“That’s concretely new information that we did not have about Joshua trees before.”

Flowering frequency

Overall, the researchers found a “slightly rising frequency” in the flowering of Joshua trees over the past 123 years. The flowering was most closely related to year-to-year variability in rainfall.

But increased flowering on its own might not necessarily be beneficial to the trees. “Flowering is just the first step in regenerating Joshua tree woodland,” Yoder said – meaning that more frequent blooms will not necessarily result in a growing population. While a flowering Joshua tree may produce thousands of seeds in a year, those seeds will result in just a few seedlings. 

Then, it’s “an even smaller subset of seedlings that start to get to something closer to an established tree over a couple of years”, he said. And some of the conditions that seem to be influencing the flowering frequency – such as contrasts in year-to-year rainfall – are “probably not good for seedling survival”.

Beyond the scientific result, Yoder is excited by the potential for further applications of the hindcast modelling. He told Carbon Brief:

“Hopefully this is something that folks can use to start to get that richer view of what climate change is doing to natural populations.”

News and views

SKYROCKETING: Researchers have warned that the current H5N1 bird flu outbreak “could reach Australia this spring”, according to the Guardian. Australia has thus far remained bird-flu-free since the strain emerged in 2020. Although some researchers think the island’s virus risk “is low” due to the country being outside the “flyways of migratory ducks and geese, [which are] the main hosts of bird flu viruses over long distances”, others say “there is still a risk, and we need to be ready for it”. Mongabay also covered the bird flu transmission, highlighting that it is the “fastest-spreading, largest-ever outbreak” and has infected “hundreds of species pole-to-pole”. The outlet reported that the virus has spread to at least 485 bird species and 48 mammals and that “the risk to humans [is] rising”.

WHEAT STOCKS: Iraq’s wheat harvest surged more than 20% this year due to a combination of “extraordinary” rainfall and improved irrigation, Bloomberg reported. The outlet added that the harvest “marked a second year of self-sufficiency in the grain” for Iraq. Meanwhile, France is facing “one of the worst harvests in the last 40 years”, according to the French agriculture ministry, as reported by Politico. The country – which is the EU’s largest producer of soft wheat – “experienced a very wet planting season last year and not enough sun in the spring and early summer”. Farmers’ unions in France are seeking governmental assistance, the outlet said.

SEABED SHAKE-UP: Leticia Carvalho was elected the new head of the International Seabed Authority, Australia’s ABC News reported, where she “will be the first woman, first oceanographer and the first representative from Latin America to serve in this position”. Carvalho unseated the incumbent secretary-general, Michael Lodge, who has presided over the ISA since 2016. The New York Times noted that Lodge “has been a polarising figure at the seabed authority” and has faced accusations that he “was too closely aligned with the mining industry”. Prior to the election, Foreign Policy Magazine profiled Carvalho and her proposed approach to the ISA.

COCA PROBLEM: Colombia’s programme for substituting coca crops in favour of legal alternatives “is failing to achieve its goals due to design, implementation and security issues”, Mongabay reported. The outlet pointed out that coca leaf growers and pickers “haven’t received the agreed technical or financial support from the government”, resulting in lower incomes and forcing them to engage in other activities, such as illegal mining, to survive. The programme was created one year after the 2016 peace deal between Colombia’s government and the Revolutionary Armed Forces of Colombia (FARC), the outlet said. It added that a recent UN assessment of the programme found that coca production has actually increased 13% between December 2021 and December 2022. 

NEW SEEDS ON THE BLOCK: On 9 August, Indian prime minister Narendra Modi launched 109 “high-yielding, climate-resilient” seed varieties at three experimental plots in New Delhi, Livemint reported. Among these was a rice variety “ideal for coastal saline areas” and a wheat variety “tolerant to terminal heat”, it added. Another Livemint long-read looked at the impact of climate change on tur dal – India’s second most consumed legume – finding that dal prices soared “by a staggering 60% between July 2022 and July 2024”. Meanwhile, an Economic Times analysis found that food inflation in India “has remained above 6% since July 2023, driven mostly by vegetables”. Overall inflation climbed to 5.1% in June this year with “most of the pressure…coming from rising food prices”, Bloomberg reported.

Watch, read, listen

‘DEFORESTATION MAFIA’: Inside Climate News delved into the legal battle to save Argentina’s Gran Chaco forest from corruption and deforestation.

‘THINKING LIKE BEARS’: NPR’s Short Wave podcast addressed what scientists are doing to conserve grizzly bears in the US – including “thinking like bears”.

VULNERABLE SCIENTISTS: A Nature career feature explored the mental health issues that rainforest scientists experience while watching “the ongoing destruction of the forest[s]”. 
REASONS TO WINE: In his Bloomberg column, David Fickling wrote about how a warming climate “could play havoc” with grape vines and imperil future wine production.

New science

Summer monsoon drying accelerates India’s groundwater depletion under climate change

Earth’s Future

New research found that changes in India’s summer monsoon, alongside warmer winters and increased demand, are driving “rapid depletion” of groundwater. Using satellite data, on-the-ground observations and a hydrological model, scientists observed that India’s groundwater declined substantially over 2002-21. They attributed the reduction in groundwater to “reduced groundwater recharge and enhanced pumping to meet irrigation demands” amid lower rainfall. They concluded: “Groundwater sustainability measures including reducing groundwater abstraction and enhancing the groundwater recharge during the summer monsoon seasons are needed to ensure future agricultural production.”

Highest ocean heat in four centuries places Great Barrier Reef in danger

Nature

Heat extremes in the sea containing the Great Barrier Reef over January-March in 2024, 2017 and 2020 were the “warmest in 400 years”, according to a new study. Using a multi-century reconstruction of sea surface temperature data on the Coral Sea on the Australian coast along with climate model analysis, the researchers highlighted the “existential threat” that human-caused climate change poses to the Great Barrier Reef ecosystem. Without “urgent intervention”, the researchers wrote that the reef risks “experiencing temperatures conducive to near-annual coral bleaching” in future. They noted: “In the absence of rapid, coordinated and ambitious global action to combat climate change, we will likely be witness to the demise of one of Earth’s great natural wonders.”

Marine heatwave-driven mass mortality and microbial community reorganisation in an ecologically important temperate sponge

Global Change Biology

The 2022 marine heatwave in Fiordland, New Zealand – the “strongest and longest” to occur there – killed more than half of the marine sponges living there, a new study revealed. The researchers analysed the impacts of the marine heatwave – which had a maximum temperature of 4.4C above average and lasted for 259 days – on a particular photosynthetic sponge. They suggested that what killed marine sponges was not bleaching – which affected more than 90% of the sponges – but the high temperatures killing their tissues directly. The research concluded that the remaining sponges “had mostly recovered from earlier bleaching”, probably due to a microbial community shift as an “adaptive response”.

In the diary

• 12-16 August: Meeting of the working group on benefit-sharing from digital sequence information | Montreal
• 26-30 August: Pacific Islands Forum Leaders Meeting | Tonga
• 28-29 August: EU Dialogue on national biodiversity strategies and action plans | Brussels

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Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to [email protected].