In Short : Record temperatures, while concerning, do not necessarily mean that climate goals and net-zero targets are dead. Such extreme weather events underscore the urgency of addressing climate change, but they do not negate the importance of global efforts to reduce greenhouse gas emissions and achieve net-zero. Rather, they highlight the critical need for swift and robust action to mitigate the impacts of climate change. Meeting climate goals requires continued commitment, international cooperation, and the implementation of sustainable practices across various sectors.
In Detail : As has been widely reported, 2023 was officially the hottest year on record. The last twelve months have exceeded 1.5° C above pre-industrial levels (the scientific baseline period used for global warming). This grim milestone has led some critics to say that reaching net-zero carbon dioxide emissions by 2050 is impossible. Doomsayers are even claiming that it is too late to stop climate change. Fortunately, science and economics show that these narratives are completely wrong. However, they are dangerous due to the backsliding and inaction they promote. Breaching the 1.5° C threshold makes the imperative for climate action stronger, not weaker.
Since we hit 1.5° C in 2023 is net zero dead? No.
While global temperatures crossed the 1.5° C level (years like 2023 with a strong El Nino are typically hotter than average) and may do so regularly by the 2030s, this does not mark the end of net zero, nor of 1.5° C pathways. Many misunderstand what 1.5° C means in a climate scenario. When the Intergovernmental Panel on Climate Change (IPCC), the world’s leading authority on climate change, refers to 1.5° C pathways, it is referring to the temperature in 2100. Net zero by 2050 represents a pathway that balances the social, economic, and technological realities of decarbonization with an emissions trajectory that will hold global warming to 1.5° C above pre-industrial levels in 2100. Conceivably, a giant asteroid that wipes out civilization could cut emissions instantly, but understandably, few would see this as a desirable pathway.
It is notable that in the IPCC’s latest report nearly all “1.5° C-aligned” scenarios actually exceed 1.5° C at some point in the 21st century before returning to 1.5° C or below at the end of the century. This is due to the unfortunate facts that: there is some degree of inertia in the climate system and we are running behind on reducing emissions. The fall in temperatures later in these scenarios depends on net-negative emissions or the use of carbon dioxide removal (CDR) methods. Essentially, in these scenarios we have borrowed against the “carbon bank” and we need to pay it back through removals. The degree to which these scenarios exceed 1.5° C is called overshoot. High overshoot scenarios are more costly due to greater investments in CDR and riskier for reasons discussed below.
Are we powerless to stop climate change after we hit 1.5° C? No.
Extensive scientific research has shown that above 1.5° C, climate risks increase in severity and potential climate tipping points become more likely. However, the climate system is remarkably complex, and we cannot know the precise temperature when a tipping point will kick in, such as when the Atlantic Meridional Overturning Circulation (AMOC), which presently makes Western Europe far warmer than its latitude would suggest, will break down. Assessing climate impacts is a game of probabilities and higher temperatures bring with them higher likelihoods of dangerous consequences. The planet is not like the bus in the movie “Speed,” which will explode as soon as a given speed is reached.
Perhaps a better analogy for climate impacts would be an ice cube in an oven. To understand how much the ice cube would melt, you need to know how hot the oven is and how long the ice cube remains in the oven (and the properties of the ice cube). Similarly, climate risks are not simply a function of the temperature above pre-industrial levels, but how long we remain there. One-hundred years at 1.5° C will be worse than one year at that temperature.
Returning to tipping points, despite their name, they are not binary. Even if triggered, how quickly they manifest greatly depends on temperature rise and how long it stays elevated. Around 400,000 years ago, at temperatures similar to present ones, Greenland lost nearly all its ice. Does that mean Greenland’s tipping point has already been reached? Perhaps. However, even if it has, the ice could melt over 1000 years or 100 years. The sea level rise in the former scenario would be far more adaptable than in the latter. Therefore, we should do all we can to slow already active tipping points and avert those we have not hit by avoiding further global warming.
Every fraction of a degree we mitigate is a win for the planet as is any shortening in the time we spend at high temperatures. There’s no magic limit that makes 1.5° C the endpoint of our climate fight. If we can’t stay below 1.5° C, we should fight for 1.6° C.
Are net-zero pathways still useful even above 1.5° C? Yes.
In the past few years, net-zero pathways have become some of the most studied scenarios ever. Complex socio-economic models have explored different decarbonization pathways for individual sectors and for the economy overall. Businesses, financial institutions, municipalities, and nations across the world are developing detailed net-zero transition plans. That work does not suddenly become useless the moment we hit 1.5° C of warming. Global warming will not stop until we reach net-zero emissions, so the decarbonization strategies developed remain critically important whether net zero is achieved in 2050 or 2060. Furthermore, the organizations with the best transition plans will be best placed to succeed in a low-carbon future.
Net zero pathways can catalyze climate action by creating a common objective in global business and trade. Financial institutions are incentivized to help their clients to decarbonize in order to hit their own net-zero targets as are purchasers with their suppliers. Countries are incentivized to implement policies to reduce emissions and work with other states to hit their Nationally Determined Contributions (their climate goals under the Paris Agreement) through activities such as internationally transferred mitigation outcomes (ITMOs) and carbon markets.
Are there reasons for optimism in our fight against climate change? Yes.
Despite the fact that emissions and temperatures are rising, there are many promising signals just below the surface.
In 2010, climate scenarios projected that business as usual (BAU) would lead to around 4 C of warming by 2100. Now, due to much stronger policies and the advances in green technologies, that BAU temperature rise is closer to 2.6-2.8 C (still dangerous, but a >1 C reduction in our trajectory). Over 90% of the world is now covered by a net-zero commitment. Net zero has gone mainstream in the private sector as well, with thousands of corporates and financial institutions committing to decarbonization and forming powerful alliances such as the Glasgow Financial Alliance for Net-Zero (GFANZ) and the We Mean Business Coalition.
As discussed above, climate tipping points have a justifiably negative connotation. However, there are positive political, economic, and technological tipping points too. At COP 28, nations collectively pledged to triple renewable energy production by 2030, which would be a massive step in reducing emissions and getting back on a net zero by 2050 trajectory. In 2023, renewables investment exceeded fossil fuel investment, and globally nearly 80% of new power infrastructure installed was from low carbon sources. Renewables installation has increased 50% from 2022 to 2023 and over one hundred nations may have already passed peak fossil fuel use.
This progress also reveals the benefits of the drive for net zero. Major long-term capital allocators need policy stability and clarity if they are to invest in developing a new power plant or bringing a new technology to market. A clear net-zero mandate encourages the private sector to innovate faster and accelerates the deployment of green solutions.
As the international community looks towards COP 29 and beyond, the commitment to climate action must remain unwavering. Our collective efforts to mitigate every fraction of warming and to decarbonize all sectors of the economy are vital. The path towards net-zero, though fraught with obstacles, remains our most promising route to a resilient and sustainable future.