"Climate adaptation finance should shift from the quantity of finance to its quality and risk-reducing impacts. The current adaptation finance system will unlikely have the desired impact of reducing climate risks to vulnerable people," says researcher Jasper Verschuur of Delft University of Technology in an article in Science, written with fellow researchers from the University of Oxford and the London School of Economics.

In a Policy Forum, Jessica Espey and colleagues argue that waning support for accurate collection and curation of population data worldwide threatens to compromise crucial evidence-based government planning. “We live in an era of seemingly unlimited data, where our digital activities may generate nearly constant information streams, yet some of our most essential infrastructure – demographic information – is deteriorating, introducing known and unknown bias into decision-making,” write the authors. Accurate population data are fundamental to effective governance. Most countries rely on national censuses, which are traditionally conducted every 10 years, to supply this information. But according to Espey et al., fewer nations are completing censuses, and many are undercounting marginalized populations. For example, at the close of the 2020 census cycle, 204 countries or territories – encompassing 85% of the world’s population – had conducted at least one census between 2015 and 2024. Yet by July 2024, 24 of these, representing roughly one-quarter of the global population, had not published their findings. This reflects a significant decline from the 2010 round, when 214 countries conducted and released census data, encompassing 93% of the global population. Moreover, even when censuses are carried out, they increasingly suffer from declining response rates and growing coverage errors – particularly in the undercounting of vulnerable populations such as ethnic minorities and young children. In the United States, for instance, the 2020 census likely missed nearly 3 million Latino individuals and close to 1 million children under the age of five.

In this Policy Forum, the authors outline several reasons for this general decline: eroding trust in institutions, COVID-19 disruptions, budget cuts to statistical offices, and collapsing international support for data collection programs. In order to address this “quiet crisis,” Espey et al. suggest adopting register-based systems, harnessing geospatial technologies and AI, and producing small-area population estimates. However, technical innovations alone are not enough, note the authors; governments must also restore public trust by showing how data informs daily life, ensuring strong privacy protections, and promoting collaboration across sectors. “In an era of growing challenges, from climate change to economic inequality, accurate population data are not a luxury – they are essential infrastructure for healthy, resilient, functioning societies,” write the authors.

The central estimate of the remaining carbon budget for 1.5°C is 130 billion tonnes of carbon dioxide (CO2) (from the beginning of 2025). This would be exhausted in a little more than three years at current levels of CO2 emissions, according to the latest Indicators of Global Climate Change study published today in the journal Earth System Science Data, and the budget for 1.6°C or 1.7°C could be exceeded within nine years.  

Exposure to wildfire smoke and heat stress can negatively affect birth outcomes for women, especially in climate-vulnerable neighborhoods, according to a new USC study. The study is one of the first to show that living in areas more susceptible to the harmful effects of climate-related exposures can significantly alter the effects of heat stress on adverse birth outcomes, even among women exposed to these conditions in the month before becoming pregnant. The research team examined 713 births among MADRES participants between 2016 and 2020. The team used data from CalFIRE (California Department of Forestry and Fire Protection) to identify the location, size, and duration of every wildland fire in southern California during the study period. They used the NOAA hazard mapping system to calculate the smoke density from each fire and applied sophisticated modeling methods to calculate ground-level smoke concentrations, estimating how much particle pollution—tiny droplets of black carbon, soot, and burned vegetation—the women in the cohort were exposed to during these events based on their daily residential location histories. They also pinpointed those LA neighborhoods that are most vulnerable to climate risks with mapping data from the California Urban Heat Island Index and the US Climate Vulnerability Index, two geospatial tools that analyze and map layers of data. They found that greater exposure to wildfire smoke and excessive heat during the month before conception and the first trimester of pregnancy was associated with greater odds of having a small-for-gestational-age (SGA) baby. For women living in the most climate-vulnerable neighborhoods, the study showed the effect of heat stress during preconception on the likelihood of an SGA birth almost doubled. The researchers also found an association between pregnant women exposed to moderate smoke-density days in the first trimester and having a low-birth-weight baby, or an infant weighing less than five pounds, eight ounces.

Prescribed burns are important for land management and preventing wildfires, but a new study finds these managed fires are also significant contributors to air pollution in the southeastern United States – particularly in areas with large minority and low-income populations. The study also finds these air quality impacts could become more pronounced in the decades ahead as the effects of climate change become more pronounced.