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
COP16 kicks off in Cali
COLOMBIA CALLING: Representatives from 175 countries are meeting in Cali, Colombia from 21 October to 1 November for the COP16 biodiversity summit, with “life on Earth on the agenda”, the New York Times reported. At the talks, countries will grapple with how to put the Kunming-Montreal Global Biodiversity Framework – often described as the “Paris Agreement for nature” – into action, alongside debates on finance for developing countries and how to best share the benefits from genetic information, the newspaper said. Carbon Brief has produced an interactive grid of where each party stands on the key negotiating issues and a live tracker of the texts under negotiation. On Tuesday, Carbon Brief’s team of five journalists on the ground in Cali held an online webinar on the key issues up for discussion at the summit. A recording is available.
HIGH-LEVEL PRESENCE: Mongabay reported that around 23,000 delegates are attending COP16, with presidents or heads of state from Brazil, Guatemala, Guinea-Bissau, Haiti, Mozambique, Peru and Suriname expected to be present. (The Earth Negotiations Bulletin noted that the summit “is the largest UN biodiversity conference to date”.) The outlet added that the conference also aims to adopt a work programme for Indigenous peoples and local communities. El Espectador reported that the Development Bank of Latin America (CAF) will invest $300m in the protection of important ecosystems across the region, including the Amazon, the Antarctic and Patagonia. The president of CAF, Sergio Díaz-Granados, said they will deliver a tool for identifying high-quality projects to be funded.
PLANS AND PLEDGES: A joint investigation by Carbon Brief and the Guardian found that 85% of countries had failed to meet a UN request to publish new pledges on how they plan to tackle biodiversity decline before COP16. Just 25 nations and the EU released new national biodiversity strategies and action plans (NBSAPs) ahead of the summit. Since then, a further 10 countries have come forward with NBSAPS, including COP16 host Colombia. Colombia’s NBSAP pledges to extend protected areas from 24 to 34% of national territory and increase the bioeconomy’s contribution to national GDP from 0.8 to 3%. Carbon Brief will be updating its NBSAP tracker later this week.
Water woes
STRESSED OUT: New analysis from the US-based thinktank the World Resources Institute found that “one-quarter of the world’s crops are grown in areas where the water supply is highly stressed, highly unreliable or both”. Three staple crops that together provide more than half of the world’s calories – rice, wheat and corn – are “particularly vulnerable”, according to the analysis. It added that both rainfed and irrigated crops “face growing threats”, with the former imperilled by “erratic weather patterns” and the latter facing “increasing competition over shared water supplies”. According to the report, “demand for water to irrigate crops is projected to rise by 16% by 2050, compared to 2019”.
TRAGEDY OF THE COMMONS: Covering the report, Grist wrote that water stress “stems partly from a common tendency to take water for granted and treat it like an endlessly renewable, on-demand resource”. Sam Kuzma, one of the authors of the report, told the publication: “Because we don’t put a value on water, you can irrigate and not pay much at all for the water that you’re using…That means we can be pretty reckless with how we’re growing and in what environments.” The analysis “spells trouble for global food security”, Grist wrote, noting that major agricultural exporters, including India, are among the countries most at risk of increasing water stress.
ROME DECLARATION: At the World Food Forum last week, hosted by the UN Food and Agriculture Organization in Rome, member states adopted the Rome Declaration on Water Scarcity in Agriculture. According to Down to Earth, “the countries committed to mobilise greater political support in terms of policies, legal and institutional frameworks, access to financing and responsible water governance”. FAO director general Dr Qu Dongyu told the plenary session: “The solutions we develop must reflect the interconnected nature of water security, agrifood systems and climate resilience.” According to the FAO press release, “by 2050, more than half the global population will live in areas at risk of water scarcity at least one month a year”.
Spotlight
‘The planet doesn’t have time to lose’
Carbon Brief’s entire food, land and nature team is on the ground in Cali, Colombia to report on the UN biodiversity talks. In this spotlight, Carbon Brief outlines what has happened so far at COP16.
Hola from Cali, where the UN biodiversity summit COP16 has kicked off this week.
Thousands of negotiators, observers, activists and journalists have descended on the city – the country’s “salsa capital” – for detailed nature discussions over the coming two weeks.
Far from the harsh lighting and long corridors of other COPs, Cali delegates are treated to mountain views in the distance and large overhead fans staving off the October heat in one of the world’s most biodiverse countries.
It has not all been smooth sailing so far, however, with packed buses transporting sweating delegates, congested roads, poor internet connections and winding security queues on the first day of the summit.
COP16 comes two years after countries signed off on a global biodiversity deal aiming to halt and reverse nature loss by the end of this decade.
Since this agreement, countries have been figuring out how to put in place these goals on a national level.
Hot topics
Negotiators are discussing a wide range of issues, including the implementation of biodiversity goals and how to scale up nature finance.
Bernadette Fischler Hooper, the head of global advocacy at WWF, told a press briefing on 21 October that resource mobilisation was hotly debated at the pre-COP16 implementation talks last week.
For example, countries are split on whether to develop a new global fund for biodiversity – to be controlled by the COP – or stick with the current fund. Negotiators are trying to break the “deadlock” on this issue over the next two weeks, she noted.
Other discussions centre around agreeing rules around digital access to genetic information, Indigenous peoples’ rights and monitoring for the Global Biodiversity Framework.
“The planet doesn’t have time to lose,” Colombian environment minister and COP16 president Susana Muhamad said at the summit’s opening ceremony.
Speaking via telecast, UN chief António Guterres also urged countries to “make peace with nature” – referencing the COP16 theme.
Security fears
More than 10,000 police officers are in place across the city amid threats from a rebel group to disrupt COP16.
Speaking at a press conference on 21 October, Cali’s mayor, Alejandro Eder, said that security was the first issue tackled when the city was selected to host COP16.
Eder assured the safety of COP16 attendees, but Colombian president Gustavo Petro last week said he was “nervous” that “something bad” could happen at the start of the summit, according to Colombia’s El Heraldo newspaper.
Eder noted that COP16 was organised in “record time”, given that cities usually have two years to prepare. (Turkey withdrew as COP16 host last year after severe earthquakes killed more than 40,000 people. Cali was confirmed as the new host in February 2024.)
Elsewhere, nearly 2,000 Indigenous peoples from Colombia took to the streets of Cali on 21 October calling for nature to be respected. More protests are expected throughout the summit.
Carbon Brief’s team of five nature journalists will be closely tracking the negotiations on the ground in Cali over the next two weeks.
News and views
REEF IT AND WEEP: The mass bleaching of coral reefs worldwide since early 2023 “is now the most extensive on record”, the US National Oceanic and Atmospheric Administration (NOAA) told Reuters. Satellite data showed a “staggering 77%” of global reefs so far have “been subjected to bleaching-level heat stress…as climate change fuels record and near-record ocean temperatures across the world”, the newswire added. “We’ve eclipsed the previous record by 11.3% and…in half the amount of time,” Dr Derek Manzello, coordinator of NOAA’s Coral Reef Watch, told Axios. CNN said that scientists have called for an emergency session on coral reefs at COP16 “in response to the bleaching record”.
‘NATURE-POSITIVE’: A record number of companies are expected to be at COP16, and they are “increasingly touting their ambitions to be ‘nature-positive’ alongside their net zero targets”, the Financial Times wrote. According to the newspaper, which looked at the rapid proliferation of the term “nature-positive” since COP15 in 2022, it implies “halting and reversing biodiversity loss, targeting an overall increase in nature…by 2030, relative to a 2020 baseline”. However, it adds that scientists and environmentalists are worried that states and firms “are starting to brandish the term as a buzzword” before a comprehensive and credible definition of nature-positive and its metrics exists.
GLOBAL ECOSYSTEM ATLAS: At COP16, the Group on Earth Observations (GEO) launched the proof-of-concept of the Global Ecosystems Atlas, a tool for mapping and monitoring the world’s ecosystems. According to a GEO press release, the atlas provides information on ecosystem extent, condition and potential risks, drawing on inputs from high-quality maps and new maps based on field data and AI. The atlas aims to support “tracking [progress on] the Global Biodiversity Framework, develop national ecosystem maps…and inform private sector reporting on nature-related risks”, the press release added.
THE ROOF IS ON FIRE: Forest fires have intensified and become more widespread “amid global heating, particularly in the high northern latitudes such as Canada and Siberia”, researchers wrote in the Conversation. Their new study found that global carbon emissions from forest fires have grown by 60% over the past two decades, with the “largest contributions com[ing] from fires in Siberia and western North America”, the authors added. “We had to check the calculations because it’s such a big number,” lead author Dr Matthew Jones told the New York Times. Elsewhere, research covered by Carbon Brief revealed that a long-term decline in area burned globally by wildfires due to land-use change has almost entirely been offset by increases caused by warming.
DYING PLANET: Wildlife populations worldwide have “plunged” by an average of 73% in the last 50 years according to the latest Living Planet report, the Guardian reported. However, it adds that the Living Planet index is “weighted in favour of data from Africa and Latin America” and the metric has faced criticism for “potentially overestimating wildlife declines”. Vox, covering the report, wrote that it “underscores [that] we are living in a time of profound biodiversity loss” and that “calculating a single figure to encompass all of this loss isn’t easy”. At the same time, scientists not involved in the report called its metrics “misleading”, the story added. A ZSL scientist quoted by Vox said that “it’s also possible that the [Living Planet Index] actually underestimates the scale of declines”. Our World In Data published a guide to understanding the index and “what it does and doesn’t mean”.
Watch, read, listen
FOREST LOSS: Mongabay looked at how Indonesia’s plan to boost renewable energy could lead to Indigenous communities losing “huge swathes of their forests to biomass plantations”.
EYES ON SOUTH AMERICA: Analysis in the Guardian discussed how Colombia and Brazil “have the chance of a lifetime to save the Amazon” in hosting key upcoming global events.
SNAIL’S PACE: Ahead of COP16, NPR’s All Things Considered radio show spoke to wildlife biologist Dr David Sischo about what it’s like to work with Hawaii’s endangered tree snails.
COUNTING MOTHS: Sundance award-winning documentary “Nocturnes” followed ecologist Dr Mansi Mungee counting hawk moths in the lush forests of north-eastern India.
New science
- A new study found that nearly half of the proposed indicators for measuring progress on the Kunming-Montreal Global Biodiversity Framework could involve community-based monitoring programmes. Researchers in Nature Sustainability wrote that greater involvement of citizens could “enhance local to national decision-making”.
- A 1% increase in deforestation in the Brazilian Amazon was linked with a 6.3% rise in malaria cases the following month, a new study in Proceedings of the National Academy of Sciences found. Using sub-annual data, researchers showed that deforestation increases malaria transmission, especially in areas with high amounts of forest cover.
- Increasingly dry conditions under a changing climate will pose a significant threat to frogs and other water-sensitive animals, according to new research in Nature Climate Change. Researchers combined maps of drought risk and frog and toad habitats to find that nearly 7% of frog and toad habitats will become “arid-like” by the end of the century.
In the diary
- 21 October-1 November: COP16 UN biodiversity conference | Cali, Colombia
- 25 October: Kiribati presidential election
- 4-5 November: UN Water meeting | New York
- 5 November: US election
- 11-22 November: COP29 UNFCCC climate conference | Baku, Azerbaijan
Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to cropped@carbonbrief.org.
The post Cropped 23 October 2024: COP16 kicks off; Water woes; Coral bleaching ‘worst ever’ appeared first on Carbon Brief.
Cropped 23 October 2024: COP16 kicks off; Water woes; Coral bleaching ‘worst ever’
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest