Abstract: The new and updated emission reduction pledges submitted by countries ahead of the Twenty-Sixth Conference of Parties represent a meaningful strengthening of global ambition compared to the 2015 Paris pledges. Yet, limiting global warming below 1.5 °C this century will require countries to ratchet ambition for 2030 and beyond. Here, we explore a suite of emissions pathways to show that ratcheting near-term ambition through 2030 will be crucial to limiting peak temperature changes. Delaying ratcheting ambition to beyond 2030 could still deliver end-of-century temperature change of less than 1.5 °C but would result in higher temperature overshoot over many decades with the potential for adverse consequences. Ratcheting near-term ambition would also deliver benefits from enhanced non-CO2 mitigation and facilitate faster transitions to net-zero emissions systems in major economies.
School Authors: Alicia Zhao, Yiyun 'Ryna' Cui
Other Authors: Lauren Harry-Villain, Yann Briand, Henri Waisman, Frederic Rudolph, Catherine Hall, Harro van Asselt, Mark Gjerek, Rico Merkert, Marcio de Almeida D'Agosto, George Vasconcelos Goes, Daniel Neves Schmitz Gonçalves, Ricardo Delgado Cadena, Maria Rosa Munoz, Dipti Gupta, Amin Hassani, Jordi Tovilla, Thalia Hernandez, Nnaemeka Vincent Emodi, Sidsel Ahlmann Jensen , Hilton Trollip