42 reports in this theme, newest first.
By the 2090s, 4.3 to 9.3 billion people will live with frequent heat, extreme rain or long dry spells, up from 3.4 billion. The exposed population ages fast: heat exposure among people 65 and over rises nearly tenfold, to 1.3 billion. If schooling keeps rising and protecting as it has, harm falls by 70–84% in three pathways, but under SSP3 protection only holds harm level, and heat harm rises 39%.
Droughts have barely become more frequent, but they have become hot. Half of warm-season drought months in 1995–2024 were also extremely hot, up from three in ten in 1951–80 and seven in ten in 2021–24. Dry-to-wet whiplash is up 30%, and hot-dry years produce the great smoke and dust events. By the 2090s, 0.34 billion people would live with two or more compound hazards on a low-emissions path, 5.2 billion on a high one.
1.66 billion people live where two or more climate hazards overlap, but only 158 million of them also have limited means to adapt. They are concentrated in the heat-and-drought belt from Senegal to Pakistan and on cyclone coasts from Madagascar to Haiti. By 2050 that overlap nearly triples to 455 million, led by Nigeria. Halving poverty and strengthening coping would cut it to 263 million, more than lower emissions alone (356 million), though not in the most fragile states.
Multi-domain shock years rose from about 6% of countries a year before 2020 to 9% since, after 33% in 2020. The observed network has a sink: economic shocks, internet shutdowns and governance shocks raise the next year's risk of displacement or mortality shocks 2.5, 2.0 and 1.6 times. Low-income countries carry eleven times the multi-domain burden of rich ones, and twenty countries with 705 million people face a 30% or higher modelled risk of multi-domain shocks in 2026.
The world adds 1.43 billion people by 2050, 69% of them in cities and 57% in sub-Saharan Africa. People living with 30 or more days a year above a 35 °C heat index more than double, from 1.9 to 4.1 billion. Warming drives 1.74 billion of that rise and population growth 0.44 billion, and growth lands disproportionately in hot places. City dwellers in 100-year flood zones, 507 million today, are heading for 630–690 million.
Countries vulnerable in 2000 have closed their human-development gap at about 0.3% a year, a half-life of two centuries. Those that avoided reversals closed it three times faster, while reversals erased 13% of their gains. Higher human development makes reversals shallower and polycrisis risk lower (r = −0.84). Faster convergence with halved reversals would bring 38 of 60 vulnerable countries past an HDI of 0.70 by 2050, against 17 at the recent pace.
Every national architecture has a weak link: the median country's weakest function trails its average by 16 points, and decoupling, the most common gap, barely tracks income. In 2020–2023 national capacities explained almost none of the growth and inflation damage, but steering was the exception, associated with 62 fewer excess deaths per 100,000 and a 5.7-point smaller rise in hunger. Thin buffers leave 3.5 billion people relying on a global backstop that covers a fraction of need.
About 11.6 million people a year die in six channels that polycrisis prevention targets. Matching the best quarter of income peers would protect 4.6 million of them and reaching the next income tier 7.0 million, but doing both would protect 8.6 million. The burdens cluster in the same 55 countries and share drivers such as health coverage and sanitation, and closing the gaps by 2040 would protect about 172 million lives by 2050.
In 2022 the median fuel importer's bill jumped from 4.5% to 7.4% of GDP, and the jump tracked how much each country imported, not how clean its power was (r = −0.08). Import bills are mostly oil and gas for transport, heat and industry, so the transition protects only when it reaches those uses. When it does, it also cuts the 86% of fossil air-pollution deaths borne by importers and the emissions behind climate risk.
Burning coal, oil, gas and biofuels caused 48% of the 3.8 million deaths from outdoor fine particles in 2017, the same combustion that drives climate change. Each million tonnes of fossil CO₂ carries about 105 deaths a year in lower-middle-income countries and 9 in rich ones, so poorer countries, which emit 11% of fossil CO₂, bear 34% of fossil-fuel air-pollution deaths. Cleaning the air must be paired with methane cuts: alone it adds 0.26°C by 2050, but with methane cuts only 0.02°C.
Each 0.1 rise in the Human Development Index goes with about 63% fewer people hit by climate disasters, 62% fewer near-poor and 25% less death from communicable disease. Within countries over time, the share affected by climate disasters falls 40% per 0.1. Yet human development gains in 2019–2023 were half those of the 2000s, the gap between low- and very-high-HDI countries has stopped closing, and development has not damped growth volatility or pandemic mortality. Those tail risks need their own institutions.
After a severe climate shock, GDP per person in low- and lower-middle-income countries falls by 1.7%, sinks to about 5% below its previous path within four years and is still 3.7% lower after eight. Upper-middle-income countries recover within four years, and earthquakes leave no lasting scar. Low-income countries now suffer climate shocks in a quarter of all years, only one in five of these has any recorded damage, and the income gap between the median rich and poor country has grown from 18 to 25 times since 1990.
Since 1975 the world's urban centres have added 2.1 billion people, and growth has leaned into the floodplain: the urban population in 100-year river flood zones tripled to 507 million while cities as a whole grew 2.3 times, with one new resident in six settling in a flood zone. Six in ten new city dwellers settled in cities exposed to at least one major hazard, and 746 million now live where two or more compound. Most of the growth still to come is unbuilt — the cheapest moment for safer settlement decisions.
The water polycrisis has two faces. In 35 countries with 4.1 billion people, from Egypt to India and China, water is physically scarce: withdrawals exceed 40% of supply, agriculture takes three-quarters and aquifers are falling. In 47 countries with 1.6 billion people, mostly in Africa, water is plentiful but nearly a third of people lack basic water, unsafe water kills at six times the rate of well-served countries and grids hang on hydropower. They meet in Sudan, Afghanistan and Yemen — and each needs a different fix.
In 35 countries with 1.45 billion people, from Nigeria to Bangladesh, fine-particle pollution is stuck high or still rising while income stays below $10,000 a head — and growth has not cleaned the air of the poorest third of countries at all. The loop runs both ways: poverty means smoky fuels and weak regulation, and pollution costs 3.7 years of life expectancy in lower-middle-income countries and erodes human capital. China turned the corner at $14,000 a head and India at about $7,000 — proof that clean air can come early, as growth policy rather than its reward.
Humanity's centre of gravity is drifting 1,700 km towards the hot belt from West Africa to South Asia just as that belt crosses danger-level heat. By the 2090s, 2.2 billion people live with a month or more of it in a middle-of-the-road world and 5.0 billion in a fragmented, high-emission one — nearly half of them people not yet born in places not yet dangerous. Low emissions and education-led development each cut that exposure by half or more, and because half of it sits on 0.5% of inhabited land, protection can be targeted.
Thirty-six countries with 3.0 billion people combine high climate hazard, high pollution exposure and weak coping capacity — across the Sahel, West and Central Africa and South Asia. The opportunity is concentrated too: the 60 countries breathing 25 µg/m³ or more emit 74% of the world's coal CO₂ and half its greenhouse gases, so in a handful of airsheds the same coal and methane cuts that slow warming would clean the air for billions.
Disasters kill far fewer people than they did — 6 per million a year in the 2010s against 99 in the 1960s — because capacity rose faster than threat. Within countries, each extra year of adult schooling has cut deaths per 1,000 people affected by about a third. Projected to 2100, that capacity keeps winning in most futures, but not in a fragmented, high-warming SSP3 world, where population and hazard outpace schooling and expected deaths rise in two-thirds of countries.
Development has been dismantling the slow crises: since the early 2000s child deaths fell in 98% of developing economies, emissions intensity in 88% and hunger in 76%. The fast systemic crises did not follow: debt service improved in only 31%, conflict in 39% and inflation in 46%, and income growth explains none of them. Beyond growth itself, only government effectiveness and clean water predict broad crisis reduction — and with convergence now stalled at 49% of economies, the missing floors are institutional.
Digital rails speed up crisis response — India, Brazil and Pakistan paid emergency cash within 7–8 days in 2020 — but they do not replace a capable state. Across 207 shocks since 1991 and the COVID recession, government effectiveness predicts recovery far better than internet use. The exception is telling: where governance is weak, every 10 extra points of account ownership before COVID went with about 7 percentage-point-years less lost output by 2023. Digital infrastructure multiplies thin state capacity most.
Scarcity is an accelerant, not a detonator. Drought cuts cereal yields by about 6% and doubles the odds of a crop failure, but in the same country an ordinary dry year barely changes the risk of war. Severe droughts raise the chance a new conflict starts the next year by about 60%, and in fragile states local droughts shift fighting toward communal and militia violence. Violence concentrates where scarcity meets weak states: 24 such countries, 7% of humanity, suffered 37% of conflict deaths in 2016–24.
The 2023 headline was six of nine planetary boundaries breached; by 2025–26 it is seven, all worsening. Measured as a multiple of the disturbance each boundary allows, humanity has used 2.1 times its CO₂ allowance, 3.1 times its climate-forcing allowance, about 2.7–2.9 times its nitrogen and phosphorus allowances and 11 to 111 times its extinction allowance. Each boundary translates into a budget, a floor, a ceiling or a ban — and the ozone layer shows a breached boundary can be brought back.
Where coping capacity is strong, recorded deaths from floods, storms, droughts, landslides and wildfires stay near 0.6 per million people a year whether hazard is low or high. Where it is weak they rise to 8.7 per million in the most exposed third — a 14-fold gap. About 14,000 recorded deaths a year are avoidable at that benchmark, and the true toll is larger because heat deaths are counted almost only in rich countries.
Air pollution currently hides a large share of greenhouse warming: sulphur dioxide alone has offset about 0.4°C. Cleaning the air without also cutting methane adds warming in the IPCC's own scenario data, while cleaning the air and cutting methane together removes almost all of that penalty by 2050. Pollution and climate are one feedback system, and the levers that work on both — methane, black carbon and ozone precursors — come first.
Humanity will live about 739 billion person-years between 2025 and 2100. On current trends, 180 billion of them will be spent under at least two of three hazards: polluted air, a hot climate and a high-risk country. Counting exposure cumulatively shows that clean air and resilience with peace each avoid more of those years this century than the gap between warming pathways, though mitigation decides how many people end up near the edge of the human climate niche.
Across 191 countries and 18 indicators, about half of what makes risks travel together is poverty: average link strength halves once income is held constant. What survives is a tighter web centred on conflict, displacement, resource dependence and rapid population growth. Countries stressed in three or more domains are almost all unstable, and the hubs point to where intervention breaks the most links at once.
Electric-car sales are on an S-curve that takes them from 10% to 90% in about ten years, and solar power in about seventeen, but the energy system's low-carbon share is moving at a pace that would take 170 years. A transparent race model shows that keeping peak warming below 2°C needs the whole system to move at roughly wind's pace, and below 1.7°C at solar's. The budget for 1.5°C runs out around 2028 on every path.
From 2000 to 2024, about 174 million children died before their fifth birthday, more than ten times the 14.9 million excess deaths of the pandemic's first two years. Today 69% of those child deaths fall in the high-risk countries that hold a quarter of humanity. Matching the best quarter of each income group would avert 2.4 million child deaths a year, nearly half the total, and 34 million more by 2050 than on current trends.
Even if no hazard worsened, the share of humanity living in today's high-risk countries would rise from a quarter to 43% by 2100, because population is growing fastest where risk is highest. About half of the 9.5 billion babies due between now and 2100 will be born in those countries. Combining UN population projections with the INFORM risk map shows who is exposed, where and in which generation, and how far reducing risk could offset demography.
A quarter of humanity, 2 billion people, lives in countries at high or very high risk of humanitarian crisis, and all 16 of the highest-risk countries score 8.4 or more out of 10 for conflict hazard. Mapping 191 countries on the INFORM Risk Index shows that hazard is not destiny. Coping infrastructure improved in 154 countries over 2017–2026 while institutions stalled, and matching each country's income peers would cut the population at high risk by more than half.
Disasters, heat, pollution, violence and the climate damage locked in by each year's emissions already cost between 1.2 and 23.5 per cent of world output a year, depending on what is counted. Over 2025–2100 that adds up to hundreds of trillions to several quadrillion dollars, and prevention would cost a fraction of it.
What if the polycrisis outran humanity's capacity to manage it? The Polycrisis Apocalypse, a term coined by H Heuristics, names a slow collapse of industrial civilisation followed by centuries of regression. Past collapses, a stress-versus-repair model readers can run and today's ledger of ten crisis domains show how it could happen, and what keeps it hypothetical.
Exposure did not decide how hard the 2021–23 food-price cascade hit; falling currencies did. Tracing that shock month by month from gas to fertiliser, grains and household food inflation in 183 countries — and the 2026 Strait of Hormuz shock along the same chain — gives a framework for when to diversify, decouple, buffer and absorb.
Food, oil, markets, policy, conflict and disasters rarely go wrong in the same year: their year-to-year correlation averages 0.12. In the 2020s they did, with an average of 3.5 of six acute indicators in their worst quartile each year against 0.7 in the 2010s, on a chronic floor of record temperatures, conflict and displacement.
Seventy-three countries are both highly vulnerable to shocks and poorly prepared to adapt, including 23 of the 24 low-income economies. Mapping the pressures converging on the world system against the adaptive capacity of 190 countries, and the financial buffers between them, shows where shocks become crises — with a country explorer built on the ND-GAIN index.
The case for investing in adaptation and mitigation together is physical and well established. The obstacle is not the argument but the cash flow: an avoided loss has no revenue line, so private capital funds about nine per cent of adaptation. This report sets out five instruments that convert avoided losses into something financeable, and how to use them without splitting the asset.
Nexus disruptions travel along whichever link is tightest: gas into fertiliser into food in 2022, drought into hydropower and into shipping lanes in 2023 and 2024. Clean technologies break those particular chains — and create new ones. This report maps four substitutions, what each buys, and what each newly requires.
Climate change and air pollution come out of the same combustion, which has made it natural to treat them as one problem. They differ in residence time by five orders of magnitude, in the geography of their harm, and in the sign of their effect on the planet's energy balance — and each difference changes what a combined strategy can do.
Every serious polycrisis strategy names the same four elements, and the list has never been the problem. The four differ in who captures their benefit and in whether anyone but the beneficiary can supply them — which determines the instrument that can deliver each, and explains why combined strategies underperform their parts.
Adaptation is counted as a stock of assets, but what protects people is a service that keeps working, and a service runs on a chain. Reliability multiplies rather than averages, so where an investment sits in the network matters more than what it costs — and polycrisis is the case where the links fail together.
Prevention is appraised against doing nothing. Its real alternative is emergency response — already being paid for, repeatedly, at surge prices, on crisis financing, leaving no asset and restoring the exposure that produced the loss. The obstacles are institutional, not economic.
The clean transition is usually argued as climate policy — a cost accepted now for a distant temperature. Read instead as risk-mitigation infrastructure, it lowers four coupled dangers at once: climate destabilisation, air-pollution mortality, energy insecurity and coercive energy geopolitics. The operative variable is not ambition but deployment.