Arctic winters are long and harsh, yet have warmed in recent years with unclear impacts on Arctic ecology. In this issue, Pekka Niittynen and colleagues show that winter conditions are the strongest environmental variable relating to fine-scale patterns in tundra vegetation, with summer temperatures impacting coarser patterns. However, landscape heterogeneity can add complexity to the response of lichens, bryophytes and vascular plants, like this snow buttercup (Ranunculus nivalis) that was surprised by a blizzard on Mount Saana, Finland.

See Niittynen et al. and News & Views by Bjorkman and Gallois

Many marine species have migrated towards the poles as water temperatures warm. In this issue, Heidi Fuchs and colleagues show that, in contrast, benthic invertebrates on the Northwest Atlantic continental shelf are pushed into warmer waters due to changes in timing of spawning and transport. This transport away from thermal niches could lead to increased mortality for these species, which include some commercial shellfish such as scallops.

See Fuchs et al.

Gaps in geographic coverage of species abundance data, especially in the tropics, makes determining species' responses to climate change difficult. Writing in this issue of Nature Climate Change, Tatsuya Amano et al. analyse 1.3 million records of 390 waterbird species at 6,800 sites around the world to reveal that increasing temperature can lead to abundance declines in waterbird species at lower latitudes, highlighting the foggy future facing the diversity of life in the tropics — including these lesser flamingos pictured in Namibia.

See Amano et al.

Climate change impacts on agriculture differ between regions, and will increase hunger globally. Writing in this issue of Nature Climate Change, Charlotte Janssens et al. show that reducing tariffs and other barriers to international trade would mitigate this impact; however, trade integration requires a careful approach to avoid reducing domestic food insecurity in food exporting regions.

See Janssens et al. and News & Views by Nechifor and Ferrari

The large-scale mechanisms causing regional drying are not well understood. Writing in this issue of Nature Climate Change, Celine Bonfils et al. demonstrate through models and observational data that human-caused changes in greenhouse gases and aerosols have led to detectable global and hemispheric signals in the combined behaviour of precipitation, temperature and aridity since the 1950s.

See Bonfils et al.

Evapotranspiration links productivity with water cycling between land and atmosphere and is restricted by plant responses to soil moisture and vapour pressure deficit stresses. In this issue, Liu et al. show that a model including plant hydraulics better describes the response of evapotranspiration to stress from vapour pressure deficit and soil moisture under rising temperatures than approaches common in Earth system models.

See Liu et al.

A soft coral sits at a depth of 2,200m on a small ridge (“Te Kawhiti o Maui Potiki”) near the Cook Islands. Marine biodiversity is at risk as the ocean warms, but currently the focus has been on the surface ocean, as the deep ocean warms less. In this issue, Brito-Morales et al. show that climate velocities (the speed and direction of isotherm displacement) are faster in the deep ocean than at the surface. Projections show this will continue, with implications for the ability of deeper marine life to adapt.

See Brito-Morales et al.

Snowmelt runoff represents an important source of water for many regions of the world. The amount and timing of snowmelt is impacted by climate change, with implications for water resource management. In this issue, a study by Qin et al. shows that basins in Asia, central Russia, the western US and southern Andes are particularly vulnerable to changes in snowmelt since they rely on this water for crop irrigation. A study by Livneh and Badger shows that shifts in mountain precipitation from snow to rain decreases the predictability of drought in the western USA.

Coal use is responsible for a large proportion of climate damages, including carbon dioxide emissions, and contributes to public health problems such as respiratory diseases. In this issue, a study by Sebastian Rauner and colleagues shows that phasing out coal brings substantial environmental and health benefits that outweigh direct policy costs, providing incentives for immediate climate action.

See Rauner et al.

After a year filled with fires around the world, we present a collection of Comments and Correspondences in this issue on the theme of fire and its implications in a warming world.

Mountain forest drought. Increases in water consumption from vegetation (green water) at the expense of streamflow in rivers (blue water). Fatichi and colleagues quantify this for a 2003 European Alps heatwave and drought, highlighting underappreciated vulnerability of blue water resources to future warmer summers. Such a finding has implications for vegetation functioning and water resource management of mountainous regions.

See Fatichi et al. and Maxwell

One of hundreds of nocturnal migrant species that will pass over North America, this Wilson's Warbler may travel upwards of 6,000 kilometres each season to reach its wintering or breeding grounds. Climate change affects the timing of bird migration, which can lead to mismatch with resource availability. Horton et al. show that migration shifted earlier in spring and autumn in the United States during the past 24 years; warmer seasons were predictive of earlier peak migration dates.

See Horton et al. and Diehl