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.

This is an online version of Carbon Brief’s fortnightly Cropped email newsletter. Subscribe for free here.

Key developments

Latin America news roundup

TREE FELLING FALLS: Political shifts in Brazil and Colombia have “had a significant impact on tree felling”, with large reductions in deforestation occurring in both countries over 2023, according to analysis from the University of Maryland and the World Resources Institute that was covered by BBC News. Tree loss in the Brazilian Amazon decreased by 39%, although in the Cerrado – an important savannah in Brazil – it increased by 6%. In Colombia, primary forest loss decreased by nearly 50%, compared to last year. But, the outlet added, “increased tree felling and fires in Bolivia, Laos and Nicaragua wiped out many of these gains”. 

WHERE THERE’S SMOKE: According to satellite data released last week, Venezuela “is battling a record number of wildfires”, fuelled in part by intense drought in the region, Reuters reported. More than 30,000 “fire points” were recorded in the country during the first three months of the year. The newswire wrote: “Man-made fires that are often set to clear land for agriculture are spreading out of control thanks to high temperatures and low rainfall in northern South America, as well as a lack of prevention planning, researchers say.” A University of Oxford fire researcher said that the fires “could be a worrying sign for what’s ahead” when Brazil enters its dry season.

COMMISSION CHANGE: The scientific community must “speak out strongly” against proposed changes to Mexico’s National Commission for the Knowledge and Use of Biodiversity (CONABIO), two academics wrote in an editorial in the journal Science. They explained that the government intends to “reduce CONABIO from a multi-ministry federal government agency to a branch within the environment ministry” and argued that this change would “strip CONABIO of its independent voice, credibility and influence on national and international policy”. The government is expected to make a final decision by the end of this month.

DENGUE ‘SURGE’: The Pan American Health Organization (PAHO) warned of a “surge in dengue cases in the Americas”, with more than 3.5m cases recorded to date – “three times more cases than those reported for the same period in 2023”, which was itself a record year, PAHO director Jarbas Barbosa said. According to PAHO: “Several environmental and social factors contribute to the spread of dengue, including rising temperatures, extreme weather events and the El Niño phenomenon.” Urbanisation and population growth also play a role, the organisation added.

Africa drought ‘disaster’

NATIONAL EMERGENCIES: More than 24 million people in southern Africa face hunger, malnutrition and water scarcity due to the combined impact of drought and floods, according to a warning from the charity Oxfam, CNN reported. It comes after Zimbabwe joined Zambia and Malawi in declaring a state of disaster over the drought, according to Sky News. Zimbabwe president Emmerson Mnangagwa made the emergency declaration in a speech on 3 April, where he called for $2bn (£1.6bn) in humanitarian aid, the broadcaster said. The Associated Press (AP) spoke to a mother affected by the drought in Zimbabwe.

CLIMATE ROLE: The “erratic” weather in southern Africa, which has lurched between drought and floods in recent months, is likely “spurred” by human-caused climate change, which is making extreme events more unpredictable, the AP said. It added that conditions have been worsened by El Niño, the naturally occurring climate phenomenon that periodically affects much of the globe. In southern Africa, El Niño “means below-average rainfall” and “sometimes drought”, the newswire reported.

EXTREME CONTINENT: Many other parts of the continent continued to face severe – and, in many cases, record-breaking – extreme weather. Much of northern Africa continued to face extreme heat, with the Moroccan city of Oujda recording a  “minimum temperature” for April that was 7C higher than the previous record, according to a Twitter account tracking extreme temperatures. That temperature was close to the all-time record, logged in the month of July. (“Minimum temperature” refers to the coolest temperature in a 24-hour period, with high minimum temperatures indicating dangerously hot nights.) West Africa also continued to face record heat. Carbon Brief reported on how Africa’s most populous nation, Nigeria, was coping with the extreme temperatures.

Spotlight

The ‘grave threat’ of ghost roads

In this spotlight, Carbon Brief reports on a new study detailing the impact of “ghost roads” on deforestation rates in the Asia Pacific region.

“Ghost roads” – illegal or informal roads that do not appear on any map – are fast expanding in biodiversity-rich tropical nations.

Carved out by farmers, miners, loggers, land grabbers and drug traffickers, these illicit roads give more direct access to pristine tropical forests – and help extractors carry out their activities while evading detection by authorities or NGOs.

The absence of ghost roads from official records or international datasets makes understanding the scale of their impact on tropical forests extremely difficult. 

A new study published in Nature this week aimed to reverse this.

“I think we all knew that ghost roads were a serious problem, but they hadn’t been studied in a concerted way,” study author Prof Bill Laurance, a conservation biologist at James Cook University in Cairns, Australia, told Carbon Brief.

Volunteer army

The research team focused on three tropical islands in the Asia Pacific: Borneo, Sumatra and New Guinea. 

To try to understand the extent of ghost roads on the islands, the researchers deployed an army of more than 200 trained volunteers.

Using satellite imagery, these volunteers studied over 1.42m plots, each one square kilometre in area, noting down the existence of roads that were missing from leading global datasets.

Study lead author Jayden Engert, a conservation ecologist and PhD student at James Cook University, told Carbon Brief that a broad range of people volunteered to help out with the mapping effort:

“We found volunteers through many different avenues, chiefly by advertising within our university and at other universities. We also ran a volunteer Map-athon with the Facebook group ‘Wild Green Memes for Ecological Fiends’, which brought in a decent amount of volunteers and also helped to raise awareness of the issue.”

Ghosts detected

The mapping effort revealed 1.37m km of ghost roads – 3-6.6 times more roads than were present in leading road datasets.

“I was blown away by how many unmapped roads there were,” Engert told Carbon Brief.

To understand how the ghost roads could be affecting deforestation rates, the scientists developed a map of their study area and quantified the percentage of forest loss in each plot.

They then used modelling to determine how the forest loss correlated with 38 biological and socioeconomic factors related to tree cover, including population density, distance to the nearest city and protected-land status – as well as ghost-road density and distance from ghost roads.

The research found that ghost-road density had by far the strongest link with forest loss out of all of the 38 factors studied. 

Furthermore, ghost-road building “almost always preceded local forest loss”, the researchers wrote in their study.

They also found that the relationship between road density and forest was nonlinear, “with deforestation peaking soon after roads penetrate a landscape and then declining as roads multiply and remaining accessible forests largely disappear”.

They concluded by saying:

“Collectively, our findings suggest that burgeoning, poorly studied ghost roads are among the gravest of all direct threats to tropical forests.”

Laurance told Carbon Brief that their findings are likely to apply to other parts of the tropics:

“There’s absolutely no doubt in my mind that other developing tropical nations are facing similar challenges with ghost roads. We also have been working in the Amazon and central Africa for the past several decades, and there we see many similar and equally daunting realities on the ground.”

News and views

FARM FLU: The US Department of Agriculture has confirmed cases of the “highly pathogenic” avian influenza in dairy cows in Idaho, bringing the number of confirmed outbreaks to 12 herds across five states, with other tests ongoing in presumptive positive cases. The country’s largest fresh egg producer also reported an outbreak, leading to “rising concern” despite assurances that the “risk to the public remains low”, the Associated Press reported. The detection of the virus in cattle raises “critical questions about whether the country is equipped to handle an influenza outbreak after the coronavirus pandemic…exposed the weaknesses in the nation’s public health infrastructure and decimated the public’s trust in key federal agencies”, the Washington Post reported.

INDIGENOUS INDONESIANS: Indonesian president-elect Prabowo Subianto must prioritise ratifying the country’s Indigenous Peoples bill, two Indigenous-rights activists argued in China Dialogue. The bill was first proposed in 2009, but president Joko Widodo failed to ratify it despite “repeated promises to do so”, the writers noted, adding: “Prabowo’s new government appears set to continue expanding Indonesia’s domestic resource-processing capabilities…signal[ling] the continued, unjust plunder of Indigenous territory.” Indonesia is home to around 22 million Indigenous people and more than 2,500 Indigenous communities. They face “deforestation, agricultural crises, marginalisation and discrimination and the usurpation of customary rights”, as well as voter disenfranchisement, the activists said.

NEW BIODIVERSITY CHIEF: BusinessGreen reported that German diplomat and environmental-policy expert Astrid Schomaker has been appointed the next executive secretary of the Convention on Biological Diversity (CBD), the UN body that oversees negotiations on biodiversity loss. According to the publication, Schomaker has spent the last seven years overseeing environmental diplomacy and global sustainable development at the European Commission. She replaces the acting executive secretary, British CBD veteran Dr David Cooper. Carbon Brief published an in-depth interview with the last permanent executive secretary, Tanzanian lawyer and diplomat Elizabeth Maruma Mrema, in 2022.

WHALE OF A TIME: Māori king Tuheitia Pōtatau Te Wherowhero VII and other Indigenous leaders in the Pacific have “urged the legal recognition of whales as persons with inherent rights”, according to the Pacific Islands News Association. The leaders are endorsing the He Whakaputanga Moana, or the Declaration for the Ocean, which “outlines a comprehensive plan” for protecting whales from “unsustainable practices, pollution and climate change”, the outlet explained. It will do so through establishing protected areas and integrating Indigenous knowledge with other science. Travel Tou Ariki, a high chief from the Cook Islands, said: “Whales play a vital role in the health of our entire ocean ecosystem…We must act with urgency to protect these magnificent creatures before it’s too late.”

BIG MEAT COP: Lobbyists from the world’s largest meat companies have celebrated a “positive outcome” from the last global climate summit, COP28, according to a DeSmog investigation. Speaking on a virtual panel organised by the trade outlet FeedStuffs, three representatives for US livestock firms said they were left “excited” and “enthusiastic” for their industry’s prospects after the summit, which saw countries commit to a series of voluntary pledges for tackling agricultural emissions without addressing meat consumption. Constance Cullman, the president of the US lobby group the Animal Feed Industry Association (AFIA) said COP28 left her organisation with “a far more positive outcome than we had anticipated”, according to DeSmog.

STANDING TOGETHER: Advocacy groups in Brazil, the Democratic Republic of the Congo, Guatemala, Kenya, Liberia and Mexico have launched a new initiative to protect environmental defenders, Liberia’s Daily Observer reported. The initiative will provide “partnerships, financial support and training” for civil-society organisations to protect them against the risks that environmental defenders face, such as threats, violence and smear campaigns, the newspaper said. Three environmental defenders were recently killed during protests in Kinjor, Liberia.

Watch, read, listen

WASTED WETLANDS: An investigation by Ireland’s Noteworthy found that the planting of non-native trees on peatlands could put some of the country’s “cleanest” rivers and streams at risk.

SALINE INHABITANTS: Hakai Magazine wrote about how Utah’s shrinking Great Salt Lake is imperilling the strange creatures found in its waters.

TREE SMUGGLING: A four-part investigation by the Africa Report, in collaboration with the Pulitzer Center’s Rainforest Investigations Network, examined timber trafficking from the Democratic Republic of the Congo.

ROCKY MOUNTAIN HIGH: A feature in High Country News explored how drones can be used in service of conservation of predators in the Rocky Mountains.

New science

Threat of mining to African great apes
Science Advances

Up to one-third of Africa’s great apes face risks from mining projects, new research found. The study looked at the overlap between industrial mining projects and great ape distribution in 15 African countries, excluding the Democratic Republic of the Congo due to a lack of available data. The research found that industrial mining projects overlap with the habitat of nearly 180,000 apes. It also found that the overlap was largest in west African nations, including Senegal and Sierra Leone. In the paper, the authors noted that the “rapid growth of clean energy technologies is driving a rising demand for critical minerals”, which are increasingly being mined in Africa.

The asymmetric impacts of international agricultural trade on water use scarcity, inequality and inequity
Nature Water

A new study found that the water “embedded” in agricultural trading “disproportionately benefits the rich and widens both the water scarcity and inequity gap between the poor and the rich”. Researchers used a global model of crop water requirements to simulate the amount of water used for irrigation for 26 different crops, then analysed how international trade affects water scarcity and inequity in eight countries. They found that the poorest people in developing countries “suffer[ed] from both increased water scarcity and inequity”, but poor populations in developed countries were more likely to benefit. They also identified the trade of staple crops as “the major driving factor” affecting these in most countries, due to the large volumes of staple crops traded. 

Significant shifts in latitudinal optima of North American birds
Proceedings of the National Academy of Sciences

The optimal location for North American birds has shifted northward by an average rate of 1.5km each year in response to climate change, a new study found, representing a total distance moved of 82.5km over the past 55 years. The research uses modelling to estimate the “latitudinal optima” of 209 American bird species, drawing on bird population abundance data over the past half-century. It found that one-third of the species studied showed a “significant shift of their optimum” over the study period, with birds in western North America experiencing the biggest shifts. The results “directly implicate climate-induced increases in temperature as the primary driver” of bird abundance shifts, the researchers said.

In the diary

• 10-12 April: 2024 Ocean Decade conference | Barcelona
• 16-19 April: Scoping meeting for the Intergovernmental Panel on Climate Change (IPCC) special report on cities | Riga
• 19 April: Start of India’s general election
• 23-29 April: Fourth session of the Intergovernmental Negotiating Committee to develop an international legally binding instrument on plastic pollution, including in the marine environment | Ottawa

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]