Forests provide several critical ecosystem services that help to support human society. Alteration of forest infrastructure by changes in land use, atmospheric chemistry, and climate change influence the ability of forests to provide these ecosystem services and their sensitivity to existing and future extreme climate events. Here, we explore how the evolving forest infrastructure of the Midwest and Northeast United States influences carbon sequestration, biomass increment (i.e., change in vegetation carbon), biomass burning associated with fuelwood and slash removal, the creation of wood products, and runoff between 1980 and 2019 within the context of changing environmental conditions and extreme climate events using a coupled modeling and assessment framework.

For the 40-year study period, the region’s forests functioned as a net atmospheric carbon sink of 687 Tg C with similar amounts of carbon sequestered in the Midwest and the Northeast. Most of the carbon has been sequestered in vegetation (+771 Tg C) with more carbon stored in Midwestern trees than in Northeastern trees to provide a larger resource for potential wood products in the future. Runoff from forests has also provided 4,651 billion m³ of water for potential use by humans during the study period with the Northeastern forests providing about 2.4 times more water than the Midwestern forests. Our analyses indicate that climate variability, as particularly influenced by heat waves, has the dominant effect on the ability of forest ecosystems to sequester atmospheric CO₂ to mitigate climate change, create new wood biomass for future fuel and wood products, and provide runoff for potential human use. Forest carbon sequestration and biomass increment appear to be more sensitive to heat waves in the Midwest than the Northeast while forest runoff appears to be more sensitive in the Northeast than the Midwest. Land-use change, driven by expanding suburban areas and cropland abandonment, has enhanced the detrimental heat-wave effects in Midwestern forests over time, but moderated these effects in Northeastern forests.

When developing climate stabilization, energy production and water security policies, it will be important to consider how evolving forest infrastructure modifies ecosystem services and their responses to extreme climate events over time.

Abstract: Understanding and predicting fate of global biodiversity amidst an increasingly complex and changing world is a major challenge facing the Earth-system science community.  Among the core research objectives within this challenge lies the ability to construct a comprehensive metric that not only faithfully quantifies the current and observed state of biodiversity, but also captures future trends that are driven by a variety of stressors across environmental, social, and economic systems. In order to give a better overview of our impact on biodiversity despite the obvious complexity inherent to the multi-sectoral nature of the problem, we have chosen to group together the indicators currently assessed and used internationally in a linked indicator set categorized according to the “Pressure-State-Response” framework. This approach stems from a desire to highlight and quantify the links between these different indicators in a logical and objective manner and allows us to construct a systematic synthesis of the key drivers of biodiversity. We develop a new methodology using predictive supervised learning to propose a statistical weighting of the linked indicator metric.

Abstract: The Turkish power sector achieved rapid growth after the 1990s in line with economic growth and beyond. However, domestic resources did not support this development and therefore resulted in a high dependency on imported fossil fuels. Furthermore, the governments were slow off the mark in introducing policies for increasing the share of renewable energy. Even late actions of the governments, as well as significant decreases in the cost of wind and especially solar technologies, have recently brought the Turkish power sector into a promising state.

A large-scale generation-expansion power-system model (TR-Power) with a high temporal resolution (hours) is developed for the Turkish power generation sector. Several scenarios were analyzed to assess their environmental and economic impacts.

 

The results indicate that a transition to a low-carbon power grid with around half of the electricity demand satisfied by renewable resources over 25 years would be possible, with annual investments of 3.97–6.88 billion in 2019 US$. Moreover, TR-Power indicates that the shadow price of CO₂ emissions in the power sector will be around 17.1 and 33.8 $/per tCO2 by 2042, under 30% and 40% emission reduction targets relative to the reference scenario.

 

Author's Highlights: 

• A large-scale generation expansion power system model with a high temporal resolution (hours).

• Seventeen scenarios including various growth paths, subsidy schemes, and constraints on the emissions.

• Half of the total load demand would be satisfied by renewables either by introducing a subsidy scheme or a carbon tax.

 

• CO₂ price will be around ∼17 and ∼34 $/per tCO₂ by 2042 under 30% and 40% emission reduction.

 

• Renewable share would be increased by nearly 10% with an additional annual investment of 887 M 2019 US$.