How Global Warming Persistence Would Affect Us If We Achieve the 1.5°C Target by 2100

The 1.5deg;C target mentioned in the UN Paris Climate Accords was set in 2014 by a group with varying scientific backgrounds. While the agreement aimed to limit global warming to 1.5 degrees Celsius above pre-modern levels by 2100, the feasibility of this target is questionable given current global emissions trends and the rapid growth of industrial activities in emerging economies.

Global Emissions and the 1.5°C Target

The Paris Climate Accords waited three years to seek advice from the Intergovernmental Planning Climate Change (IPCC) on how to achieve this target. The IPCC provided initial feedback that achieving the 1.5deg;C target was not feasible. However, they proposed reducing global industrial emissions to 1970s levels by 2030. Since then, global emissions have increased by 0.7% annually and are projected to continue increasing by 1.1% until 2035, largely driven by aggressive coal programs in emerging economies.

Even if all rich Western nations ceased all emissions immediately, according to calculations, it would only reduce the warming by 464 days to 4deg;C by 2100. Given that the Third World currently accounts for 68% of global emissions and is projected to increase to 85% by 2035, the 1.5deg;C target is far from being achievable.

Continuity of Environmental Effects

Despite achieving the 1.5deg;C target, continuous environmental effects would still be mitigated but less severe than higher warming scenarios:

Ocean Level Ascent

Warm expansion and cold melting would continue to drive sea levels higher, albeit more slowly than at 2deg;C or beyond. Low-lying coastal regions would remain vulnerable to flooding and erosion.

Extreme Climate Events

Extreme heatwaves, heavy precipitation, and storms would still occur but less frequently and severely, compared to higher warming levels. This would continue to challenge infrastructure, agriculture, and ecosystems.

Biodiversity and Species Loss

Coral reefs would experience significant bleaching, with up to 70-90% severely affected. Cold and snow ecosystems would face shifts in biodiversity and species loss.

Polar Ice and Permafrost

Some Arctic summer sea ice loss is plausible. Thawing permafrost could release ozone-depleting substances like methane and CO2, potentially creating positive feedback loops.

Human Health and Occupations

Populations in tropical and developing regions would still face heat stress, reduced water availability, and harvest yield decreases, but these impacts would be less extreme.

Monetary and Social Costs

Transformation costs, such as building resilient infrastructure, would continue. Some regions could still experience irreversible damages like loss of habitable land.

Benefits of Achieving the 1.5°C Objective

Meeting this target would moderate the worst consequences, such as:

Avoiding tipping points, for example, the breakdown of the Greenland and Antarctic ice sheets or large-scale Amazon deforestation. Reducing the risk of climate breakdown and ensuring more consistent food and water supplies. Protecting valuable opportunities for transformation and development to manage ongoing challenges.

Why Effects Would Continue

The target does not stop climate change but limits it. The current effects are due to past emissions, and even if emissions were radically reduced today, the inertia of the climate system would ensure that warming continues for a long time due to existing greenhouse gases in the air. Therefore, sustained mitigation and adaptation efforts will remain crucial even after achieving the objective.

Understanding and accepting these realities can help us focus on the actionable steps we can take to mitigate and adapt to climate change. It underscores the importance of continued global collaboration and innovative solutions in the fight against climate change.