The Minamata Convention on Mercury entered into force in August 2017, committing its currently 92 parties to take action to protect human health and the environment from anthropogenic emissions and releases of mercury. But how can we tell whether the convention is achieving its objective? Although the convention requires periodic effectiveness evaluation (1), scientific uncertainties challenge our ability to trace how mercury policies translate into reduced human and wildlife exposure and impacts.

Since the late Pleistocene, large-bodied mammals have been extirpated from much of Earth. Although all habitable continents once harbored giant mammals, the few remaining species are largely confined to Africa. This decline is coincident with the global expansion of hominins over the late Quaternary. Here, we quantify mammalian extinction selectivity, continental body size distributions, and taxonomic diversity over five time periods spanning the past 125,000 years and stretching approximately 200 years into the future.

Nitrogen availability is a pivotal control on terrestrial carbon sequestration and global climate change. Historical and contemporary views assume that nitrogen enters Earth’s land-surface ecosystems from the atmosphere. Here we demonstrate that bedrock is a nitrogen source that rivals atmospheric nitrogen inputs across major sectors of the global terrestrial environment.

A gap in emission inventories of urban volatile organic compound (VOC) sources, which contribute to regional ozone and aerosol burdens, has increased as transportation emissions in the United States and Europe have declined rapidly. A detailed mass balance demonstrates that the use of volatile chemical products (VCPs)—including pesticides, coatings, printing inks, adhesives, cleaning agents, and personal care products—now constitutes half of fossil fuel VOC emissions in industrialized cities.

Plastic waste can promote microbial colonization by pathogens implicated in outbreaks of disease in the ocean. We assessed the influence of plastic waste on disease risk in 124,000 reef-building corals from 159 reefs in the Asia-Pacific region. The likelihood of disease increases from 4% to 89% when corals are in contact with plastic. Structurally complex corals are eight times more likely to be affected by plastic, suggesting that microhabitats for reef-associated organisms and valuable fisheries will be disproportionately affected.

Achieving universal, safely managed water and sanitation services by 2030, as envisioned by the United Nations (UN) Sustainable Development Goal (SDG) 6, is projected to require capital expenditures of USD 114 billion per year (1). Investment on that scale, along with accompanying policy reforms, can be motivated by a growing appreciation of the value of water. Yet our ability to value water, and incorporate these values into water governance, is inadequate.

The seventh cholera pandemic has heavily affected Africa, although the origin and continental spread of the disease remain undefined. We used genomic data from 1070 Vibrio cholerae O1 isolates, across 45 African countries and over a 49-year period, to show that past epidemics were attributable to a single expanded lineage. This lineage was introduced at least 11 times since 1970, into two main regions, West Africa and East/Southern Africa, causing epidemics that lasted up to 28 years.

Climate change can influence ecosystems via both direct effects on individual organisms and indirect effects mediated by species interactions. However, we understand little about how these changes will ripple through ecosystems or whether there are particular ecological characteristics that might make ecosystems more susceptible— or more resistant—to warming. By combining in situ experimental warming with herbivore manipulations in a natural rocky intertidal community for over 16 months, we show that herbivory regulates the capacity of marine communities to resist warming.

River flood risks are expected to rise as climate change intensifies the global hydrological cycle and more people live in floodplains. Changing risk may be revealed by trends in flood frequency, magnitude, or seasonality, as well as by shifts in the mechanisms that generate inundations. However, detection and attribution of climate signals in flood records is often hampered by brief, incomplete, or poor-quality flood data. Additionally, it can be difficult to disentangle the effects of changing climate, land cover, channel morphology, and human activities.

We evaluated a program of payments for ecosystem services in Uganda that offered forestowning households annual payments of 70,000 Ugandan shillings per hectare if they conserved their forest. The program was implemented as a randomized controlled trial in 121 villages, 60 of which received the program for 2 years. The primary outcome was the change in land area covered by trees, measured by classifying high-resolution satellite imagery. We found that tree cover declined by 4.2% during the study period in treatment villages, compared to 9.1% in control villages.