Negative-emissions technology portfolios to meet the 1.5 °C target

O Rueda,J.M Mogollón,A Tukker,L Scherer

doi:10.1016/j.gloenvcha.2021.102238

O Rueda, J.M Mogollón + Show 2 more

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https://doi.org/10.1016/j.gloenvcha.2021.102238

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Abstract

Our carbon-intensive economy has led to an average temperature rise of 1 °C since pre-industrial times. As a consequence, the world has seen increasing droughts, significant shrinking of the polar ice caps, and steady sea-level rise. To stall these issues’ worsening further, we must limit global warming to 1.5 °C. In addition to the economy’s decarbonization, this endeavour requires the use of negative-emissions technologies (NETs) that remove the main greenhouse gas, carbon dioxide, from the atmosphere. While techno-economic feasibility alone has driven the definition of negative-emissions solutions, NETs’ diverse, far-reaching implications demand a more holistic assessment. Here, we present a comprehensive framework, integrating NETs’ critical performance aspects of feasibility, effectiveness, and side impacts, to define the optimal technology mix within realistic outlooks. The resulting technology portfolios provide a useful new benchmark to compare carbon avoidance and removal measures and deliberately choose the best path to solve the climate emergency.

Highlights

Large-scale negative-emissions technologies (NETs) are essential for reaching the 1.5 ◦C climate target, but they are far from an ideal solution (Anderson and Peters, 2016; Rogelj et al, 2018b)
Low-cost solutions, such as afforestation and reforestation (AR), soil carbon sequestration (SCS), and biochar (BC) may be difficult to implement (Forster et al, 2020; Seddon et al, 2020), and their effect would be vulnerable to distur bances (Fuss et al, 2018); bioenergy with carbon capture and storage (BECCS) could seriously compromise food security and biodiversity (Dooley and Kartha, 2018; Fuss et al, 2014; Kartha and Dooley, 2016), two already pressing sustainable-development challenges; and emerging technologies, such as direct air carbon capture and storage (DACCS), enhanced weathering (EW), and ocean fertilization (OF), may turn out prohibitively expensive (Keith et al, 2018; Smith et al, 2016)
NET performance widely varies among critical aspects (Fig. 5)

Summary

Introduction

Large-scale negative-emissions technologies (NETs) are essential for reaching the 1.5 ◦C climate target, but they are far from an ideal solution (Anderson and Peters, 2016; Rogelj et al, 2018b). Despite the massive ex pected scale of NET deployment, several times the scale of today’s oil industry (Caldecott et al, 2015), there is little discussion about how to approach and determine an ideal NET mix Climate stabilization requires both carbon avoidance and carbon removal measures, as even aggressive decarbonization pathways depend on significant levels of negative emissions (Gasser et al, 2015; van Vuuren et al, 2018). Negative-Emissions need Reaching the 1.5 ◦C climate target requires large-scale NET deployment, likely ranging from 150 to 1180 GtCO2 throughout the 21st cen tury (Minx et al, 2018; Rogelj et al, 2018b). SSP5 requires the highest negative emissions (1180 GtCO2) due to high energy demand and a strong preference for fossil fuels

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