Climate change: Consequences for Earth, scientists' opinions
What serious changes await our planet (photo: sciencealert.com)
2023 has become the warmest year ever recorded by humans. It is likely that temperatures were last this high around 125,000 years ago. The loss of sea ice in Antarctica is accelerating at alarming rates, along with many other indicators of rapid climate change. But does this mean that 2023 is just the first step towards irreversible changes on the planet?
RBC-Ukraine reports on the dangerous climate tipping points that Earth is facing, referencing a publication by Science Alert.
What dangerous climate changes await our planet
Most people think that an ecosystem or part of the climate system, when under stress, will react fairly predictably - double the pressure, double the impact, and so on. But this does not always happen. Sometimes a system under stress changes steadily up to a certain point, but beyond that, much larger or abrupt changes may be locked in.
Examples of such non-linear changes are tipping points that occur when the system crosses a threshold, and then the changes become self-sustaining. This means that even if the initial pressure decreases, the changes will persist until the system reaches a sometimes entirely different state.
It's like rolling a boulder up a hill. It takes a lot of energy. If the energy input stops, the boulder will roll back. But when the top of the hill is reached, and the boulder is balanced at the very top, a slight push, perhaps even a gust of wind, may be enough for it to roll down the other side.
The climate system has many potential tipping points, such as the disappearance of ice cover or the density of tropical forests, which become significantly drier and more open. It will be very difficult, practically impossible, to restore these systems once they reach a critical point.
The Global tipping points report
The Global Tipping Points Report, released at the COP28 UN climate negotiations in Dubai, presents scientific findings on negative tipping points in the Earth's system that could harm both nature and humanity. The report also includes conclusions regarding potential positive societal tipping points that could accelerate actions toward sustainable development.
"Analyzing scientific evidence of past and ongoing changes and taking into account forecasts from computer models, we have identified over 25 tipping points in the Earth's system," scientists stated.
Six of these tipping points are located in the icy parts of the planet (cryosphere), including the collapse of massive ice shields in Greenland and various parts of Antarctica, as well as local glacier flips and thawing of permafrost.
Scientists have identified over 25 tipping points in the Earth's system (photo: sciencealert.com)
16 of them are located in the biosphere - the sum of all the world's ecosystems - including the mass die-off of trees in parts of the Amazon and northern boreal forests, degradation of savannas and arid territories, nutrient overload in lakes, mass coral reef die-offs, and the decline of mangrove forests and seagrass meadows.
"We have identified four potential tipping points in the circulation of the oceans and the atmosphere, including the collapse of deep-ocean mixing in the North Atlantic and the Southern Ocean around Antarctica, as well as the disruption of the West African monsoon," say the scientists.
What global warming threatens with
Climate change poses imminent threats to the planet, driven by human activity. While precise threshold values remain unknown, current global warming of 1.2 degrees Celsius is likely to result in the widespread loss of warm-water coral reefs. Additionally, it could lead to the collapse of the Greenland and West Antarctic ice sheets, the breakdown of the North Atlantic circulation, and the local thawing of permafrost.
At a temperature increase of 1.5 degrees Celsius, vulnerable systems such as mangrove forests, seagrass meadows, and parts of boreal forests become susceptible. Some systems may also tip or lower warming thresholds due to other factors, such as deforestation in the Amazon.
If parts of the Amazon rainforest perish, an incalculable number of species could be lost, and warming would intensify further as billions of tons of carbon currently locked in trees and soils are released into the atmosphere.
Economically, this could have consequences on the order of trillions of dollars in the region and expose millions of people to extreme heat.
All these factors will negatively impact the economy, leading to further financial instability, displacement, conflict, or polarization in societies. It could hinder environmentalists' efforts to limit further tipping points in the Earth system and even lead to a shift towards a social system characterized by more authoritarianism, hostility, and alienation, potentially completely derailing the transition to stabilization.
Another risk is that most Earth systems interact in ways that destabilize each other. In the worst case, the failure of one system increases the likelihood that connected systems will also fall. This can lead to a cascade effect akin to a domino effect.
Climate change is a key factor for most of these tipping points, and the risk of crossing them can be reduced by urgently reducing greenhouse gas emissions to zero.
To prevent tipping points in the biosphere, we will also need to rapidly reduce habitat loss and pollution while simultaneously supporting ecological restoration and resilient livelihoods.
Read also about when all life on Earth will cease to exist.
