Global terrestrial drought and its projected socioeconomic implications under different warming targets

Area of Science:

• Climate Science
• Environmental Science
• Risk Assessment

Background:

• Increasing global temperatures exacerbate drought frequency and intensity worldwide.
• Strategic Environmental Assessment (SEA) and adaptation strategies are crucial for climate resilience.
• Existing SEA methods require enhancement to accurately quantify future drought impacts.

Purpose of the Study:

• To develop an innovative approach for strengthening drought risk assessment within SEA.
• To quantify the impacts of future temperature increases on drought characteristics.
• To integrate novel drought projection methods into SEA for improved climate-resilient planning.

Main Methods:

• Integrated multiple data sources (reanalysis, satellite observations, model simulations) for drought projection.
• Utilized terrestrial water storage (TWS) anomalies to identify drought conditions.
• Employed random forest (RF) models to determine drought drivers and copulas for bivariate drought hazard analysis.

Main Results:

• Over 50% of the global surface faces increased drought risk at 2.0°C warming; this rises to over 60% at 2.5°C.
• Significant reductions in joint return periods for drought duration and severity are projected in tropical/subtropical regions.
• Drought events are projected to increase global GDP and population risks by 37% and 24%, respectively, with continued warming.

Conclusions:

• The study provides an enhanced SEA framework for accurately assessing drought risks and vulnerabilities.
• Findings support the development of effective adaptation strategies for ecosystems and human communities.
• The research underscores the urgent need for climate-resilient planning to mitigate escalating drought impacts.