A research and development investment strategy to achieve the Paris climate agreement.

Climate stabilization requires the deployment of several low-carbon options, some of which are still not available at large scale or are too costly. Governments will have to make important decisions on how to incentivize Research and Development (R&D). Yet, current assessments of climate neutrality typically do not include research-driven innovation. Here, we link two integrated assessment models to study R&D investment pathways consistent with climate stabilization and suggest a consistent financing scheme. We focus on five low-carbon technologies and on energy efficiency measures. We find that timely R&D investment in these technologies lowers mitigation costs and induces positive employment effects. Achieving 2 °C (1.5 °C) requires a global 18% (64%) increase in cumulative low-carbon R&D investment relative to the reference scenario by mid-century. We show that carbon revenues are sufficient to both finance the additional R&D investment requirements and generate economic benefits by reducing distortionary taxation, such as payroll taxes, thus enhancing job creation.

The biodiversity-wind energy-land use nexus in a global biodiversity hotspot.

Wind energy is the leading renewable technology towards achieving climate goals, yet biodiversity trade-offs via land take are emerging. Thus, we are facing the paradox of impacting on biodiversity to combat climate change. We suggest a novel method of spatial planning that enhances windfarm sustainability: investments are prioritized in the most fragmented zones that lie outside the Natura 2000 network of protected areas. We showcase it in Greece, a biodiversity hotspot with a strong climate policy and land conflict between conservation and wind energy schemes. The analysis indicates that the suggested investment zone supports wind harnessing 1.5 times higher than the 2030 national goal, having only marginally lower (4%) wind speed. It performs well for the conservation of the annexed habitats and species of the two Nature Directives and it greatly overlaps with the Important Bird Areas (93%) and the roadless areas (80%) of Greece. It also greatly overlaps (82%-91%) with the exclusion zones suggested according to three sensitivity maps for bird conservation. Since land use change triggers biodiversity decline, we underline the necessity of such approaches for meeting both climate and biodiversity goals and call for a greater environmental policy convergence towards biodiversity conservation and no net land take.

Taking stock of national climate policies to evaluate implementation of the Paris Agreement.

Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario analysis, we show that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO2eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5 °C Paris goals. If Nationally Determined Contributions would be fully implemented, this gap would be reduced by a third. Interestingly, the countries evaluated were found to not achieve their pledged contributions with implemented policies (implementation gap), or to have an ambition gap with optimal pathways towards well below 2 °C. This shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries.