The photochemical reflectance index (PRI) derived from remotely sensed data has emerged to be a pre-visual indicator of water stress. This study evaluated the impact of the varying shaded-leaf fractions on estimating relative water content (RWC) across growth stages of winter wheat using PRI derived from hyperspectral imagery. Results showed that PRI of the pure shaded leaves may yield inaccurate estimates of plant water status, but the accuracy of RWC predictions was not significantly affected.

With the recent publication of the IPCC special report on the 1.5 °C target and increased attention on carbon dioxide removal (CDR) technologies, we think it is time to advance from the current way of looking at specific strategies to a more holistic CDR perspective, since multiple "side effects" may lead to additional CO₂ uptake into different carbon pools. This paper explores potential co-benefits between terrestrial CDR strategies to facilitate a maximum CO₂ sequestration effect.

The study highlights new approaches in the investigation of past sea ice in Antarctica to reconstruct the climate conditions in earth's history and reveal its future development under global warming. We examined the distribution of organic remains from different algae at the Western Antarctic Peninsula and compared it to fossil and satellite records. We evaluated IPSO₂₅ – the sea ice proxy for the Southern Ocean with 25 carbon atoms – as a useful tool for sea ice reconstructions in this region.

We addressed how the intertwined effect of temperature and nutrients modulates the metabolic response of planktonic communities in the Red Sea, one of the warmest seas on earth. Our study unveiled that photosynthesis increases at a faster pace than respiration rates for this group of organisms formed by microalgae, bacteria, and drifting animals. This anomaly is likely due to the nature of the basin where the warmest waters are frequently enriched with nutrients, which favours microalgae growth.

Ecophysiological studies on Antarctic cryptophytes to assess whether climatic changes such as ocean acidification and enhanced stratification affect their growth in Antarctic coastal waters in the future are lacking so far. Our results reveal beneficial effects of ocean acidification in conjunction with enhanced irradiance on growth and photosynthesis of the Antarctic cyrptophyte Geminigera cryophila. Hence, cryptophytes such as G. cryophila may be potential winners of these climatic changes.

To obtain nearly 30 years of global terrestrial carbon fluxes, we simultaneously incorporated in a land surface model three different time periods of two observational data sets: absorbed photosynthetic active radiation and atmospheric CO₂ concentrations. One decade of data is enough to improve the modeled long-term trends and seasonal amplitudes of the assimilated variables, particularly in boreal regions. This model has the potential to provide short-term predictions of land carbon fluxes.

Atmospheric methane has risen rapidly since 2008 and has become more depleted in ¹³C, in contrast to the trend towards more ¹³C enrichment in the late 20th century. Many have used this isotopic evidence to infer an increased biogenic source. Here I analyze the ¹³C trend with the consideration that methane from shale gas is somewhat depleted in ¹³C compared to other fossil fuels. I conclude that shale gas may be responsible for a third of the global increase from all sources.

Efforts to understand the global phosphorus (P) cycle are limited by the scarcity of global data on rates of soil P processes, as well as on its environmental controls. Here, we present a novel approach using radiophosphorus labeling of soils, which allows for the measurement of fluxes of abiotic and biotic soil P processes. This approach is also suitable for strongly weathered and P-depleted soils. Biotic processes are corrected for abiotic processes by comparing live and sterile soils.

This study presents an estimate of global terrestrial photosynthesis. We make use of satellite chlorophyll fluorescence measurements, a visible indicator of photosynthesis, to optimize model parameters and estimate photosynthetic carbon uptake. This new framework incorporates nonlinear, process-based understanding of the link between fluorescence and photosynthesis, an advance on past approaches. This will aid in the utility of fluorescence to quantify terrestrial carbon cycle feedbacks.

Recent studies suggest spatial variations of the marine particle flux length scale. Using a global biogeochemical ocean model, we investigate whether changes in particle size and size-dependent sinking can explain this variation. We address uncertainties by varying aggregate properties and circulation. Both aspects have an impact on the representation of nutrients, oxygen and oxygen minimum zones. The formation and sinking of large aggregates in productive areas lead to deeper flux penetration.