Comment in 2022

Monitoring marine plastic pollution requires repeated, long-term, global and harmonised observations of plastic presence, quantity and type, which satellites can provide. To convince space agencies to take action, coordinated activities are urgently needed to agree on target environments and to integrate in situ and satellite-derived measurements.

Environmental cycling of microplastics and nanoplastics is complex; fully understanding these pollutants is hindered by inconsistent methodologies and experimentation within a narrow scope. Consistent methods are needed to advance plastic research and policy within the context of global environmental change.

Solving the plastic waste problem requires pre- and post-consumption actions. Behaviour change interventions — including nudges, norm messages and education — offer opportunities to reduce demand for single-use plastic while industry-wide solutions and governmental policies are developed and expanded.

Floating plastic is accumulating in the five subtropical oceanic gyres, but little is known about their composition, sources, and fate. Monitoring has provided insight into persistence and accumulation processes in the North Pacific Ocean, but their relevance in other gyres is unknown. Identifying the sources of plastics, in all subtropical gyres, is necessary for cleanup efforts to be effective.

The large quantities of plastics stored in landfills and dumpsites are often overlooked when discussing plastic pollution. Improperly managed waste disposal sites can leak plastics to the environment, requiring immediate action. Mitigation must be supported by research to quantify the scale of the problem and prioritize efforts.

The development of a global legally binding treaty by the UN to end plastic pollution is underway. To be effective, the global treaty requires new levels of transparency, disclosure and cooperation to support evidence-based policymaking that avoids the fragmented and reactionary policies of the past.

Plastic pollution is widely presented as a waste problem, resulting in proposed solutions that target end-of-life waste management and consumer behaviour. This framing misrepresents the entangled global social and ecological challenges of the plastic crisis, which must be recognised for effective, equitable and sustainable responses.

Third Pole Environment programme was established to characterize Earth System interactions over the broader Tibetan Plateau region. Despite past successes, more insight and actionable knowledge are needed, particularly regarding the Asian Water Tower’s imbalance and associated ecosystem feedbacks and geohazards, and the teleconnections between the Third Pole and other regions.

Water quality of the Asian Water Tower is far less studied than water quantity, but expected increases in upstream riverine chemical fluxes and lowland pollutant release could exacerbate water quality deterioration downstream. Data sharing, integrated modelling, and joint actions are needed to mitigate this problem.

The Tibetan Plateau plays a central role in global atmospheric circulation, acts as a key biodiversity hotspot, and delivers fresh water for more than 20% of the global population. Projecting its future uplift and erosion trajectory over geological time can offer potential testable hypotheses into interactions between tectonic and surface processes.

Entrepreneurs are important actors in effectively managing marine plastic pollution, but they face unique challenges in developing sustainable business models within an unsustainable system. However, marine plastic entrepreneurs can engage with these tensions to create far-reaching social change beyond their business models.

The EU needs an integrated nutrient directive that regulates the agricultural application of nitrogen and phosphorus to prevent ecosystem degradation and support the Farm to Fork initiative. This directive must go beyond the current, inadequate regulations by considering nutrient balances and accounting for regional differences.

Following record-level declines in 2020, near-real-time data indicate that global CO₂ emissions rebounded by 4.8% in 2021, reaching 34.9 GtCO₂. These 2021 emissions consumed 8.7% of the remaining carbon budget for limiting anthropogenic warming to 1.5 °C, which if current trajectories continue, might be used up in 9.5 years at 67% likelihood.

Human mobility was drastically reduced during COVID-19 lockdowns, and could surge beyond pre-pandemic levels as restrictions ease. A classification scheme enables robust comparative analyses of pauses and pulses in human mobility — from anthropauses to anthropulses — providing invaluable insights into anthropogenic environmental impacts.

Antarctic sea ice extent reached a new record low of 1.965 million km² on 23 February 2022. This extent is approximately 32% below climatological values and might indicate a transition to new, more extreme, annual fluctuations.