For the first time in the history of COP climate summits, the US – the world’s largest historical emitter – has not sent a delegation to the talks.
Back in January, newly inaugurated US president Donald Trump signed a letter to the UN to trigger the start of a US withdrawal from the Paris Agreement for a second time.
Although this process is not yet complete, the White House confirmed earlier this month that no “high-level officials” would be attending COP30 in Belém, Brazil.
The US joins Afghanistan, Myanmar and San Marino as the only countries not registering a delegation for the summit, according to Carbon Brief’s analysis of the provisional lists of delegates published by the United Nations Framework Convention on Climate Change (UNFCCC).
Despite these absences, more than 56,000 delegates have signed up to COP30, provisionally placing the summit as one of the largest in COP history.
This is despite the run-up to the negotiations being dogged by reports of a shortage of beds and “sky-high” accommodation costs.
Brazil even offered free cabins on cruise ships moored in Belém to delegations from low-income nations who were otherwise unable to attend.
According to the provisional figures, 193 countries, plus the European Union, have registered a delegation for the summit.
Unsurprisingly, the largest delegation comes from COP30 hosts Brazil, with 3,805 people registered.
This is followed, in order, by China, Nigeria, Indonesia and the Democratic Republic of the Congo.
This year also sees the largest number of “virtual” delegates, with more than 5,000 people signed up to attend the talks online.
Party delegations
With 56,118 delegates registered, COP30 is provisionally the second-largest COP in history, behind only COP28 in Dubai, which was attended by more than 80,000 people.
This is the provisional total, based on the delegates that have registered to be at the summit in person. At recent COPs, the final total is at least 10,000 lower, which would drop COP30 down to the fourth largest.
(The UNFCCC releases the final figures – based on participants collecting a physical badge at the venue – after the summit has closed.)
The chart below shows how the provisional figures for COP30 compare to the final totals in past COPs – going back to COP1 in Berlin in 1995.
The participant lists provided by the UNFCCC are divided between the different types of groups and organisations attending the summit. The largest group at COP30 is for delegates representing parties. These are nation states, plus the European Union, that have ratified the convention and play a full part in negotiations.
This group adds up to 11,519 delegates – the fourth largest behind the past three COPs.
(In keeping with recent COPs, the UNFCCC has published spreadsheets that name every single person that has registered for the summit – excluding support staff. Previously, COPs have typically included thousands of “overflow” participants in which countries and UN agencies could nominate delegates without their names appearing on their official lists.)
For consistency with Carbon Brief’s analysis of previous COPs, the above chart includes overflow delegates as a single group. However, the participant lists do divide the overflow delegates between parties and observer groups. Including the overflow numbers approximately doubles the total for party representatives to 23,509.
US no-show
Overall, of the 198 parties to the UNFCCC, 194 have registered delegations for COP30.
The most notable absentee is the US, which has been present at every other COP in history – even throughout Donald Trump’s first presidency.
On average, the US sends a delegation of around 100 people, typically making it one of the larger groups at the talks.
The absent parties – Afghanistan, Myanmar and San Marino – have been more sporadic attendees at past COPs.
Despite reports of a “logistical nightmare” hosting a COP summit in the Amazon, there has been no drop-off in the number of countries registering delegations for COP30.
In addition to hotel rooms and rental properties in Belém, beds have been made available on cruise ships, in converted shipping containers and in motels that Reuters primly described as being typically “aimed at amorous couples”.
Reports suggested that many developing nations considered scaling back their presence at COP30, with smaller delegations or attendees only coming for a few days.
While the average party delegation size of 59 (excluding overflows) is lower than the previous two COPs, it is similar to the average in COP26 in Glasgow and COP27 in Sharm el-Sheikh.
The map and table below present the delegation size – split between party and overflow badges – for all the countries registered for COP30. The darker the shading, the more delegates that country has signed up. Use the search box to find the data for a specific party.
The largest delegation comes from host country Brazil, with 3,805 people registered. China (789) and Nigeria (749) follow with the second- and third-largest, respectively.
Making up the rest of the top 10 are Indonesia (566), the Democratic Republic of the Congo (556), France (530), Chad (528), Australia (494), Tanzania (465) and Japan (461).
The UK comes someway down the list with a delegation of 210.
(It is worth noting that some countries – such as Brazil – allocate some of their party badges to NGOs, which can artificially inflate the size of their official delegation.)
The smallest delegation is the one person registered to represent Nicaragua. There are five delegations of two people (North Korea, Latvia, Liechtenstein, Saint Vincent and the Grenadines and Slovakia).
Ahead of COP30, Latvia's climate minister, told Reuters that the country had asked if its negotiators could dial into the summit by video call. However, Latvia does not appear to have registered any delegates to attend virtually.
In total, 40 parties registered virtual delegates. Party totals are all in single figures apart from the Philippines (31), Costa Rica (21) and Turkey (16).
Changing gender balance
The UNFCCC’s participant lists typically provide a title – such as Mr, Ms, Sr or Sra – for each registered delegate. In the past, this has allowed Carbon Brief to work out the balance of men to women in the delegations that each country has sent to a COP.
(This analysis always carries the caveat that the titles are designated by UNFCCC and not by Carbon Brief. In addition, Carbon Brief recognises that gender is not best categorised using a binary “man” or “woman” label and appreciates that the UNFCCC’s lists may not be wholly accurate.)
Overall, the COP30 provisional list suggests an average gender balance of party delegations of 57% men to 43% women.
As the chart below shows, this makes COP29 the most balanced COP in history. For consistency, the COP28, COP29 and COP30 figures only include those on party badges, not overflow ones.
(Note: Since COP28 last year, the UNFCCC has also used titles that do not indicate gender – such as Dr, Prof, Ambassador and Honourable. Therefore, for this analysis, these non-gendered titles – which make up 1% of all the people at COP30, for example – have not been included.)
There are four party delegations this year that are all men – Tuvalu (three delegates), Niger (three), North Korea (two) and Nicaragua (one) – and one that is all women (Nauru, with five delegates).
The full list of COP30 party delegation sizes can be found here.
(For previous COPs, see Carbon Brief’s delegate analysis for COP21, COP23, COP24, COP25, COP26, COP27, COP28, COP29)
The post Analysis: Which countries have sent the most delegates to COP30? appeared first on Carbon Brief.
Analysis: Which countries have sent the most delegates to COP30?
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 rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Congress, including its climate strategy out to 2030, according to the Hong Kong-based South China Morning Post. The plan called for China to cut its carbon emissions per unit of gross domestic product (GDP) by 17% from 2026 to 2030, which “may allow for continued increase in emissions given the rate of GDP growth”, reported Reuters. The newswire added that the plan also had targets to reach peak coal in the next five years and replace 30m tonnes per year of coal with renewables.
ACTIVE YET PRUDENT: Bloomberg described the new plan as “cautious”, stating that it “frustrat[es] hopes for tighter policy that would drive the nation to peak carbon emissions well before president Xi Jinping’s 2030 deadline”. Carbon Brief has just published an in-depth analysis of the plan. China Daily reported that the strategy “highlights measures to promote the climate targets of peaking carbon dioxide emissions before 2030”, which China said it would work towards “actively yet prudently”.
Around the world
- EU RULES: The European Commission has proposed new “made in Europe” rules to support domestic low-carbon industries, “against fierce competition from China”, reported Agence France-Presse. Carbon Brief examined what it means for climate efforts.
- RECORD HEAT: The US National Oceanic and Atmospheric Administration has said there is a 50-60% chance that the El Niño weather pattern could return this year, amplifying the effect of global warming and potentially driving temperatures to “record highs”, according to Euronews.
- FLAGSHIP FUND: The African Development Bank’s “flagship clean energy fund” plans to more than double its financing to $2.5bn for African renewables over the next two years, reported the Associated Press.
- NO WITHDRAWAL: Vanuatu has defied US efforts to force the Pacific-island nation to drop a UN draft resolution calling on the world to implement a landmark International Court of Justice (ICJ) ruling on climate, according to the Guardian.
98
The number of nations that submitted their national reports on tackling nature loss to the UN on time – just half of the 196 countries that are part of the UN biodiversity treaty – according to analysis by Carbon Brief.
Latest climate research
- Sea levels are already “much higher than assumed” in most assessments of the threat posed by sea-level rise, due to “inadequate” modelling assumptions | Nature
- Accelerating human-cause