Global Warming and the 1.5°C Target: Urgency and Challenges

Likelihood of Overshooting the Target

In recent climatic studies, the likelihood of limiting peak global warming to below 1.5°C with a high degree of confidence is increasingly becoming a distant dream. The research sheds light on the grim reality that even with a moderate level of effort, this target may not be achievable. This sobering revelation comes at a time when adherence to the Paris Agreement’s ambitions is more critical than ever.

The most optimistic scenario now sees the possibility of keeping global warming below 1.6°C with a 50% chance, thanks to significant advancements in green technology. However, constraints in implementing climate policies, particularly in developing countries due to inadequate infrastructure and systemic inefficiencies, further exacerbate the situation, reducing the likelihood of achieving this new target. The variability in the likelihood, estimated between 5-45%, underscores the inherent uncertainties and hurdles in global climate action.

Implications and Projections

The consequences of failing to limit global warming are dire. A study signals that under a 3°C warming scenario, Europe could see a tripling of heat-related deaths by 2100, highlighting the urgent need for effective adaptation measures. As of now, human activities have already led to a 1.2°C increase in global average surface air temperatures above pre-industrial levels, and projections suggest a more than 50% chance of surpassing 1.5°C between 2021 and 2040 in most studied scenarios.

More alarming is the possibility of global temperatures climbing between 3.3°C and 5.7°C by 2100 if higher emissions pathways are followed. To avert such catastrophic outcomes, immediate and aggressive action is needed: GHG emissions must peak immediately and no later than 2025, followed by a reduction of 43% by 2030 and 60% by 2035 relative to 2019 levels. This pace and scale of reductions require unprecedented global cooperation and commitment.

Compounding the urgency is the Earth’s energy imbalance, which has escalated to an average of 0.9 W/m² over the past 12 years. This imbalance not only confirms perpetual warming but also portends long-term sea-level rise and other complex climatic changes. Understanding these dynamics and their cascade effects is essential in formulating comprehensive climate policies.

It is crucial to recognize that the Paris Agreement’s temperature goal is targeted at global average surface-air temperature increases averaged over 20-30 years, rather than on a yearly or shorter-term basis, which are influenced by natural climate variability. As such, efforts to mitigate global warming must be sustained and evaluated over the long term to reflect their true impact, reinforcing the importance of continuous and robust climate action strategies.