Volume 7 Issue 7, July 2017

Continued US membership in the Paris Agreement on climate would be symbolic and have no effect on US emissions. Instead, it would reveal the weaknesses of the agreement, prevent new opportunities from emerging, and gift greater leverage to a recalcitrant administration.

Discriminating the climate impacts of half-degree warming increments is high on the post-Paris science agenda. Here we argue that evidence from the observational record provides useful guidance for such assessments.

There is no longer a choice between climate policy and no climate policy. G20 finance ministers have to play a key role in implementing smart climate policies like carbon pricing. Yet they remain reluctant to take advantage of the merits of carbon pricing for sound fiscal policy.

The dramatic switch from extreme drought to severe flooding in California, and the accompanying flip from atmospheric ridge to trough in the northeastern Pacific, exemplifies the pathways to an intensified water cycle under a warming climate.

European far-right parties have been making headway and could pose a risk to climate-friendly policy.

Individuals are often asked to reduce their home energy consumption. But new research suggests that reminders of these personal energy savings may undermine public support for national-level policies.

There is widespread speculation as to whether hailstorms are getting more intense or frequent as the global climate warms. Now research suggests a potential increase in both the mean hail size and frequency of larger hail events over North America.

Ambitious greenhouse–gas emissions cuts are needed to limit the global mean annual temperature increase to 1.5 °C above preindustrial levels. A study now finds that the land sink for CO₂ appears much smaller than is currently factored into climate models, suggesting that emissions cuts may need to be even more ambitious than currently estimated.

Permafrost soils represent a massive pool of organic carbon that could be released to the atmosphere due to future climate change. A study now shows that previously frozen soil carbon contained in peatlands may make a relatively modest contribution to future methane emissions following permafrost thaw.

The planet is warming; however, this includes periods of accelerated and slowed warming. Although the tropical Pacific played a role in the recent slowdown, this study shows sea surface temperatures across multiple basins influence the rate of warming.

The acceleration of sea-level rise continues, but this has not been clear in the short altimeter record. This study closes the sea-level rise budget for 1993–2014 and illustrates the increased contribution from the Greenland ice sheet.

Significant feedbacks in energy, agriculture, land use and the carbon cycle are identified for the twenty-first century when climate impacts on land are factored into climate projections so as to allow for two-way interactions between human and Earth systems.

Climatic conditions that challenge human thermoregulatory capacity currently affect around a quarter of the world’s population annually. Such conditions are projected to increase in line with CO₂ emissions particularly in the humid tropics.

Methane fluxes from thawing peatlands in northern Canada were derived predominantly from anaerobic decomposition of recent vegetation rather than from previously frozen material — as is typically assumed.

Climate change mitigation will require both household and government action. This study shows that engaging in energy-saving behaviour at home leads to the perception that sufficient progress is being made through individual action, which reduces support for government policies.

Greater convective activity is anticipated with anthropogenic climate change. Model results now indicate that the size and frequency of large hail events will likely increase over the US, particularly in southern and central regions, increasing the risk of hail damage.

This research presents global baseline estimates of mangrove soil C stocks enabling countries to begin to assess their mangrove soil C stocks and the emissions that might arise from mangrove deforestation.

The boreal forest is being transformed by changes in its climate–fire regime. Analysis now shows that lightning drives year-to-year and long-term ignition and burned area trends in boreal North America.