A landmark climate report in late 2018 explained exactly what’s at stake if the world doesn’t limit global warming to 1.5 degrees Celsius, from the total loss of coral reefs to millions of people at risk from sea level rise. Now, a new report lays out a blueprint to keep warming in check– without, as many plans do, relying on controversial nuclear power or new technologies to capture CO2 (including machines that suck carbon dioxide from the air) that haven’t yet been proven at scale. The report says it can happen for far less money than we’re currently spending to subsidize fossil fuels.
In the project, called the One Earth Climate Model, funded by the Leonardo DiCaprio Foundation’s One Earth initiative, researchers had “the ultimate goal of finding a way to keep the global temperature rise below 1.5 Celsius without resorting to geo-engineering or nuclear,” says Sven Teske, the project’s lead scientist and research director at the Institute for Sustainable Futures at the University of Technology Sydney. “The warnings from the [Intergovernmental Panel on Climate Change] and the scientific community are clear: A world that warms beyond 1.5 Celsius is not one we want to inhabit.” The world has warmed about 1 degree Celsius so far, and we’re already seeing more catastrophic wildfires and flooding. The more the world heats up, the more existential risks we face.
The researchers took a detailed, bottom-up look at the energy sector, modeling each hour of energy use through 2050 on 72 regional energy grids, studying local solar and wind data, and projecting energy demand and the need for storage. They considered three scenarios. In one, based on projections from the International Energy Agency, they looked at how the world could continue to rely heavily on fossil fuels and warm an apocalyptic 5 degrees. In another, they modeled how the world could limit warming to 2 degrees. The last scenario looked at a 1.5-degree limit.
To stay under 1.5 degrees of warming, the report says, the world needs to move quickly to renewable energy, reaching 100% renewables by 2050. By 2020, we’ll need to be phasing out an average of two coal power plants every week. Heating, cooling, and transportation will have to shift to electricity on a massive scale. Energy use will have to become much more efficient, with total demand dropping by more than a third.
The changes in the energy system–all based on currently available technology–can get the world most of the way to the 1.5-degree target. “Negative emissions,” or sucking carbon out of the air, is necessary for the rest. While other climate models include new carbon-capture technology, the researchers found that planting and protecting forests could take up enough carbon to avoid unproven solutions. Through changes in land use, particularly large-scale reforestation in tropical forests and reducing logging, it’s possible to sequester around 150 gigatons of carbon dioxide. “Forests do a much better job as natural carbon sinks–and they are an asset for our planet that should be conserved for a wealth of reasons, which is why we propose the restoration of forests and a moratorium on deforestation within this generation,” Teske says. (The report acknowledges that this solution has risks, including the possibility that increasing wildfires burn down trees, or prolonged droughts mean that soil isn’t taking up as much carbon.)
A fast transition to renewable energy would also create more jobs than the business-as-usual path, the report says. By 2050, on a 1.5-degree pathway, the world would have 46.3 million energy sector jobs, versus 29.9 million in a 5-degree scenario. The transition would be expensive, with a cost of around $1.7 trillion a year. But governments currently spend an estimated $5 trillion a year to support fossil fuels, or $10 million a minute every day. Shifting to clean power could happen at a third of the cost.
The report makes it clear that it’s technically and economically possible to make the changes we need. The gap is political and social. “Staying below 1.5 Celsius is still possible, but it’s going to take radical action by governments to implement the right policy frameworks and public mobilization on an unprecedented scale if we’re to build the zero-carbon future that the world so desperately needs,” says Teske.