IPCC’s “Global Warming of 1,5°C” Report — 10 things you need to know

Thales Dantas
3 min readOct 15, 2018

“Limiting warming to 1.5ºC is possible within the laws of chemistry and physics but doing so would require unprecedented changes,” — Jim Skea, Co-Chair of IPCC Working Group III.

IPPC’s board (via DGVN).

On October 8th 2018 the Intergovernmental Panel on Climate Change (IPCC), the leading international body for the assessment of climate change (for more info on the IPCC, view the last post about climate change related organizations), released a new its newest report — “Special Report on Global Warming of 1.5°C”. The study evaluates the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate povertyThis article will give you a quick overview of what you need to know this game-changing report.

i. The Special Report assesses energy, land and ecosystems, urban and infrastructure, and industry in developed and developing nations to see how they would need to be transformed to limit warming to 1.5°C.

ii. The report states that 2°C of global warming cap, set by the Paris Agreement, would be highly dangerous.

iii. Limiting global warming to 1.5°C would require “rapid and far-reaching” transitions in land, energy, industry, buildings, transport, and cities.

iv. Global net human-caused emissions of carbon dioxide (CO2) would need to fall by about 45 percent from 2010 levels by 2030, reaching ‘net zero’ around 2050.

v. Without such effort, we will continue at our current trajectory toward 3°C of warming. Even if we hit the 1.5°C goal, the planet will still face massive, devastating changes.

“Climate change adaptation is no longer an option, it is a necessity. This report makes it clear that the longer we delay, the more difficult and costly it will be. Professor Petteri Taalas, Secretary-general of WMO.

vi. This IPCC special report identifies two main pathways that explore global warming of 1.5°C. The first involves global temperature stabilizing at or below before 1.5°C above pre-industrial levels. The second pathway sees warming exceed 1.5°C around mid-century, remain above 1.5°C for a maximum duration of a few decades, and return to below 1.5°C before 2100. The latter is often referred to as an ‘overshoot’ pathway. Any alternative situation in which global temperature continues to rise, exceeding 1.5°C permanently until the end of the 21st century, is not considered to be a 1.5°C pathway.

vii. All pathways that limit global warming to 1.5°C with limited or no overshoot project the use of carbon dioxide removal (CDR).

viii. In general, an increase in global temperature from the present day to 1.5°C or 2°C (or higher) above pre-industrial temperatures would increase the need for adaptation. Stabilizing global temperature increase at 1.5°C would require a smaller adaptation effort than for 2°C.

ix. Limiting global warming would limit the increases in ocean temperature and acidity and decreases in ocean oxygen levels and so would reduce risks to marine biodiversity, fisheries, and ecosystems. But even with a temperature increase of 1.5°C, coral reefs are expected to decline by 70–90 percent, whereas more than 99 percent would be lost with 2°C.

x. Depending on future socioeconomic conditions, limiting global warming to 1.5°C, compared to 2°C, might reduce the proportion of the world population exposed to a climate change-induced increase in water scarcity by up to 50%.

At the same time that the predictions made by the IPCC show us a grim future, it gives us the opportunity and space to fight climate change. It urges for international cooperation, cross-sector alliances, and individual engagement in order to fight the catastrophic impacts that going beyond the set warming caps could bring.

We have the information, the pathway, and the technology to do it. The ball is in our court.

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Thales Dantas

Ph.D. candidate in environmental engineering (UFSC). Member of the WEF Global Shapers Community Sustainaiblity and Circular Economy specialist.