Human activity causes the emission of small particles such as soot from combustion into the atmosphere. These particles, also called aerosols, have a growing impact on the climate system and negative effects on human health. Further research is needed to conclusively determine whether we have already overstepped the global boundary for this kind of air pollution.
Oceans are becoming more and more acidic; their pH value is decreasing, because of more and more carbon dioxide entering the atmosphere, which dissolves in oceanic water, turning into carbonic acid. This phenomenon is impacting sea creatures and marine ecosystems, which in turn will have consequences for human beings. However, the planetary boundary for acidification has not yet been exceeded.
The availability of freshwater and moist, temperate air is crucially important for humans, plants and many other life forms. Until now, researchers assumed that we have not yet exceeded the planetary boundary for the earth’s hydrological balance. But now it appears that the ‘green water’ is falling to ever-lower levels.
Humans are encroaching more and more on the natural world, leading to more contacts between people and animals in which diseases can be transmitted. COVID-19 and monkeypox are the most recent examples. Climate change is exacerbating the problem by forcing many animals to move to new areas. They can bring diseases with them. Vaccinations can help, but we need other ways to reduce the risks.
Landslides can have devastating consequences, swallow up houses and roads, pour vast amounts of debris into valleys, and damage lives, ecosystems, and infrastructure. Such hazards could occur more often in the future, says scientist Ugur Öztürk.
Life could not exist without nitrogen and phosphorus. Like other important nutrients, these chemical elements circulate in cycles between land, water, air and living things – in quantities that ecosystems have adjusted to over the course of evolution. But humans have caused serious imbalances in these cycles. There is too much nitrogen and phosphorus in circulation.
In a few years, “climate anxiety” might be part of our everyday vocabulary. It isn’t a mass phenomenon yet, according to psychologists. However: why does the threat raised by climate change throw young people off track more easily than it does their parents’ generation?
Online shopping, streaming videos, gaming ... digital technologies are playing an ever-larger role in our everyday lives. That can be problematic for protecting the climate. It is important to use technology wisely: otherwise, we risk unnecessary waste of energy and other resources.
Biodiversity and intact ecosystems are important stabilizing factors for the entire Earth system. However, human intervention in natural systems is threatening this ecological stability. Global diversity loss has accelerated such that we have already crossed this planetary boundary.
