The two most urgent and interlinked environmental challenges humanity faces are climate
change and biodiversity loss. We are entering a pivotal decade for both the international …

BACKGROUND Oxygen concentrations in both the open ocean and coastal waters have
been declining since at least the middle of the 20th century. This oxygen loss, or …

ES 6: 3-5 Replace “It is unequivocal that emissions of the well-mixed greenhouse gases
(GHG) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2 O) from human activities …

Existing redox classifications and the calibrations of elemental proxies to modern
environmental redox scales are in need of re-evaluation. Here, we review environmental …

Coastal eutrophication and hypoxia remain a persistent environmental crisis despite the
great efforts to reduce nutrient loading and mitigate associated environmental damages …

This chapter addresses the biogeochemical cycles of carbon dioxide (CO2), methane (CH4),
and nitrous oxide (N2O). The three greenhouse gases have increased in the atmosphere …

Estuaries and coastal seas provide valuable ecosystem services but are particularly
vulnerable to the co‐occurring threats of climate change and oxygen‐depleted dead zones …

Oxygen loss in the ocean, termed deoxygenation, is a major consequence of climate change
and is exacerbated by other aspects of global change. An average global loss of 2% or more …

Dissolved oxygen concentration is a crucial organizing principle in marine ecosystems. As
oxygen levels decline, energy is increasingly diverted away from higher trophic levels into …

We report a new synthesis of best estimates of the inputs of fixed nitrogen to the world ocean
via atmospheric deposition and compare this to fluvial inputs and dinitrogen fixation. We …