Tackling climate change by adding, restoring, or enhancing forests is gaining global support. However, it is important to investigate the broader implications of this. We used a computer model of the Earth to investigate a future where tree cover expanded as much as possible. We found that some tropical areas were cooler because of trees pumping water into the atmosphere, but this also led to soil and rivers drying. This is important because it might be harder to maintain forests as a result.

Despite the ocean’s importance in the carbon cycle and hence the climate, observing the ocean carbon sink remains challenging. Here, I use an ensemble of 12 models to understand drivers of decadal trends of the past, present, and future ocean carbon sink. I show that 80 % of the decadal trends in the multi-model mean ocean carbon sink can be explained by changes in decadal trends in atmospheric CO₂. The remaining 20 % are due to internal climate variability and ocean heat uptake.

Our study explores lipid remodeling in response to environmental stress, specifically how cell membrane chemistry changes. We focus on intact polar lipids in a phytoplankton community exposed to diverse stressors in a mesocosm experiment. The observed remodeling indicates acyl chain recycling for energy storage in intact polar lipids during stress, reallocating resources based on varying growth conditions. This understanding is essential to grasp the system's impact on cellular pools.

This overview of the special issue “Global change effects on terrestrial biogeochemistry at the plant–soil interface” features empirical, conceptual and modelling-based studies and outlines key findings on plant responses to elevated CO₂; soil organism responses to warming; impacts on soil organic carbon, nitrogen and mineral nutrient cycling; and water level changes affecting greenhouse gas emissions, from the Arctic to the tropics, which are crucial for deciphering feedbacks to global change.

This study examined springs in north central Florida focusing on how interactions between the surface and subsurface affected the properties of groundwater microbes. We found that microbes reproduced at rates that greatly exceed those documented for any other aquifer. Although the groundwater discharged to spring runs contains low concentrations of nutrients, our results indicate that microbes have access to sources of energy and produce new cells at rates similar to surface waterbodies.

We explored the relationship between oxygen and stratification in the North Pacific Ocean using a combination of data mining and machine learning. We used isopycnic potential vorticity (IPV) as an indicator to quantify ocean ventilation and analyzed its predictability, a strong O₂–IPV connection, and predictability for IPV in the tropical Pacific. This opens new routes for monitoring ocean O₂ through few observational sites co-located with more abundant IPV measurements in the tropical Pacific.

This study stands out for thoroughly examining CMIP6 ESMs' ability to simulate biogeochemical variables in the southern South China Sea, an economically important region. It assesses variables like chlorophyll, phytoplankton, nitrate, and oxygen on annual and seasonal scales. While global assessments exist, this study addresses a gap by objectively ranking 13 CMIP6 ocean biogeochemistry models' performance at a regional level, focusing on replicating specific observed biogeochemical variables.

In this work, we measured the chemistry of seawater from samples obtained from different depths and locations off the east coast of the Northeast Greenland National Park to determine what is influencing concentrations of dissolved CO₂. Historically, the region has always been thought to take up CO₂ from the atmosphere, but we show that it is possible for the region to become a source in late summer. We discuss the variables that may be related to such changes.

The Mediterranean Sea is regarded as a climate change hotspot. Documenting the population of planktonic foraminifera is crucial. In the Sicily Channel, fluxes are higher during winter and positively linked with chlorophyll a concentration and cool temperatures. A comparison with other Mediterranean sites shows the transitional aspect of the studied zone. Finally, modern populations significantly differ from those in the sediment, highlighting a possible effect of environmental change.