The Stark Difference Between Global Warming Of 1.5°C And 2.0°C

By Andrea Willige

When it comes to climate, a seemingly small temperature change can make a world of difference – literally.

Since the Industrial Revolution, global temperatures have been rising – by .07 degrees Celsius between 1880 and 1980, and by twice that rate over the last 40 years, due to human activity and the corresponding influx of greenhouse gases into the atmosphere. The result of our warming planet is extreme weather and unprecedented droughts and floods that harm people the world over.

To stabilize the climate, the Paris Agreement aims to limit global temperature increases to well below 2°C (or 3.6 Fahrenheit) compared to pre-industrial levels. The treaty’s target is 1.5°C (or 2.7 degrees Fahrenheit) by 2050. Whether we reach 1.5°C or 2°C – a modest-sounding increase of .5°C degrees – has dramatic implications for the health of the planet and its inhabitants. Not surprisingly, the Paris Agreement’s target was a key topic of focus at COP26 in Glasgow, with some advocating for the ‘softer’ 2°C goal while others argued for the ‘harder’ 1.5°C goal.

The severity of 1.5°C vs. 2°C

A 1.5°C increase in global temperatures will have a significant impact on the climate. But a 2°C increase will be far worse, according to the Intergovernmental Panel on Climate Change (IPCC).

As IPCC's special report explains, close to three times as many people would be regularly exposed to extreme heat than in a 1.5°C scenario. The projected rise in sea levels by 2100 would increase by 0.06 meters over and above a 1.5°C rise. We would also lose twice as many plants and vertebrate species and three times as many insects. Marine fisheries would see catches decline twice as much – 3 million metric tons – than at 1.5°C. And crop yields could decline more than twice as much in some areas, threatening food security.

The legacy of fossil fuels

The IPCC, which was created by the United Nations Environment Programme (UN Environment) and the World Meteorological Organization (WMO), points out that, despite all efforts to date, global warming is intensifying. The planet has experienced a temperature increase of 1.18°C so far and could well exceed 1.5°C within the next 20 years. The report stresses that unless we can realize rapid, large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond our reach.

To limit global warming to 1.5°C, we need to lower CO2 emissions 45% from 2010 levels by 2030 and achieve net zero emissions around 2050.

To keep within 2°C, we need to lower CO₂ emissions from 2010 levels by a minimum of 25% by 2030, and reach net zero by 2070. To achieve the more ambitious goal of 1.5°C, a 45% reduction on 2010 levels will be needed by 2030, followed by net zero around 2050.

The initial CO₂ abatement brought about by the COVID-19 pandemic offered a glimpse of the necessary reduction while highlighting the tension between economic growth and the ongoing reliance on fossil fuels. Countries with a continued commitment to fossil fuels will have to find different approaches, including new technologies, to hit the elevated carbon abatement targets.

Decarbonization solutions are emerging

Shouldering these challenges will depend on deploying net zero technologies effectively and at scale.

However, in its Net Zero By 2050 report, the IEA predicts that existing or planned policies for the energy transition would only result in marginal improvements. Despite a substantial ramp up in renewable energy generation and a decline in coal, the agency expects natural gas supply to continue growing significantly and oil to plateau over the next three decades.

To reach net zero CO₂ emissions by 2050, the share of renewables in total electricity generation globally will need to increase from 29% in 2020 to over 60% in 2030, and to nearly 90% in 2050.

Having such high proportions of intermittent renewable electricity in the power mix will only be possible through substantial growth of energy storage solutions. At the same time, hydrogen and carbon sequestration – such as carbon capture, utilization and storage (CCUS) and direct air capture (DAC) – will be even more critical on the path to 1.5°C.

Decarbonizing to limit global warming is an opening for the investment community as well as bigger industry players, such as the oil majors or large infrastructure companies.

The value chain for captured CO₂ needs to be established, building on its use as a raw material for the chemical sector, in carbon-reinforced concrete, as well as its conversion to carbon black for industry and its role in making proteins for animal feed and for agriculture.

Meanwhile, first blue and then green hydrogen are expected to become competitive with gray (fossil-derived) hydrogen by the early 2030s. This will add to their appeal both to current users of hydrogen and to those exploring new applications: Hydrogen could complement or replace natural gas used in power generation, industrial processes and transportation.

A $50 trillion opportunity

Carbon pricing is another lever governments can use to confront climate change. The energy research and advisory firm Wood Mackenzie recommends a ‘step change’ in carbon pricing by raising it to $160 per metric ton of CO₂ by 2030. Currently, the cost of carbon in the European Union Emissions Trading System, for example, is around $95 per metric ton as of January 21.

But it’s not all about sticks – penalizing the offenders – it’s also about carrots.

Getting on the 1.5°C trajectory is a substantial investment opportunity, one that Wood Mackenzie puts at some $50 trillion. This includes building out new energy capacity, creating sufficient energy storage, developing electrolyzers for green hydrogen and putting in place the surrounding infrastructure.

This is as much of an opening for the investment community as for bigger industry players such as the oil majors or large infrastructure companies. But the onus is on governments to set up supportive regulatory frameworks and incentives to kick-start and de-risk the market, especially for decarbonization technologies still in their infancy.

Half a degree can make a dramatic difference, and these players took steps toward the 1.5°C pathway at COP26, according to the IEA’s assessment of updated pledges. They represent important progress, to be sure, but these projections also suggest that a lot more needs to be done to move us closer to the mark.

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About the author

Andrea Willige has spent many years creating content for the international business and technology press, working on behalf of some of the world’s largest technology companies.