Irrigation of biomass plantations may globally increase water stress more than climate change

Abstract

Bioenergy with carbon capture and storage (BECCS) is considered an important negative emissions (NEs) technology, but might involve substantial irrigation on biomass plantations. Potential water stress resulting from the additional withdrawals warrants evaluation against the avoided climate change impact. Here we quantitatively assess potential side effects of BECCS with respect to water stress by disentangling the associated drivers (irrigated biomass plantations, climate, land use patterns) using comprehensive global model simulations. By considering a widespread use of irrigated biomass plantations, global warming by the end of the 21st century could be limited to 1.5 °C compared to a climate change scenario with 3 °C. However, our results suggest that both the global area and population living under severe water stress in the BECCS scenario would double compared to today and even exceed the impact of climate change. Such side effects of achieving substantial NEs would come as an extra pressure in an already water-stressed world and could only be avoided if sustainable water management were implemented globally.

Energy potentials and water requirements from perennial grasses on abandoned land in the former Soviet Union

“…Management of land and water resources stands at the heart of sustainable bioenergy deployment strategies. While irrigated bioenergy deployment increases bioenergy potentials with reduced land requirements, uncontrolled irrigation expansion risks causing water stress [7]. Our findings suggests that irrigation can be sustainably considered in up to 18 Mha of abandoned land.…”

“…Competition for land with food production and nature conservation limits the land availability for bioenergy. Irrigation of bioenergy crops can ramp up bioenergy supply with reduced land requirements but may pose increased risks of water scarcity [6][7][8].…”

Revisiting “Additional Carbon”: Tracking Atmosphere–Ecosystem Carbon Exchange to Establish Mitigation and Negative Emissions From Bio-Based Systems

“…Climate benefits are not a guaranteed outcome of bio-based systems, but rather the result of systems thinking and designincluding innovations in technology, assessment, and policyto maximize mitigation potential while minimizing the risk of unintended consequences. Prime and even marginal arable land are a finite resource, and arbitrarily-wide deployment of any land-based mitigation approach will at some point conflict with the food system (Fuhrman et al, 2020;Stenzel et al, 2021) and/or with biodiversity preservation (Stoy et al, 2018;Seddon et al, 2019). In light of these challenges, some recommend taking a highly precautionary approach to the development and deployment of bio-based systems (Searchinger, 2010;DeCicco and Schlesinger, 2018).…”

Investigating the effects of climate change, drought, and agricultural sector policies on the trend of the water poverty index in Iran

“…Increasing water demand due to population growth, urbanization, industrialization, expansion of agricultural activities, and economic growth are some reasons for water scarcity (Duc et al 2021;Xiao et al 2021aXiao et al , 2021bXiao et al , 2022Yang & Usman 2021). In addition to the above-mentioned factors, there are some other parameters, such as climate change, drought, and inefficient water management policies, especially in the agricultural sector (Kandel et al 2017;Salman et al 2021;Stenzel et al 2021) which play a significant role in assessing water stress accurately, determining the areas with water shortage, and developing effective management policies. Examining the current water resource situation and its future changes to identify the depth of the water crisis in each region and provide proper management plans requires the use of appropriate scientific multi-criteria indicators (Ray & Shaw 2019).…”