Washington, Apr 11 (AP) President Donald Trump's sweeping global tariffs have stirred widespread anxiety about a severe economic downturn -- and curiosity, for some, about how it might affect the world's warming climate.

Experts say a slowdown in international trade might have a brief and slight benefit in reducing greenhouse gas emissions, which come in part from fuels like gas and oil that are used to move goods around the world via ships, planes and vehicles.

But any such benefit in reducing emissions, which cause climate change, will be swamped by sharply rising costs worldwide that will hurt efforts to transition to green energies.

“I would say it might help the climate in the first year or two if we have a downturn in economic activity or a recession, which no one wants,” said Rob Jackson, head of the Global Carbon Project, a group of scientists who monitor greenhouse gas emissions yearly. “But it will hurt the climate long-term because tariffs impact clean tech more than most other industries because of trade with China.” “Any emissions reduction would be temporary,” said Dan Jasper, senior policy advisor at Project Drawdown. “I'm deeply skeptical that this would have positive impacts on climate change and in particular the energy transition.” Climate experts have closely studied changes in world economic activity in the last century, from the Great Depression to the recent coronavirus pandemic, looking for insights to help shape policies to reduce carbon emissions.

A major US-China trade war would be a very different dynamic than other recent slowdowns, as China produces much of the equipment needed for a transition to renewable energies, such as solar panels.

Trump imposed, then suspended for 90 days, import taxes on dozens of countries Wednesday. He escalated his trade war with China, raising tariffs on its products to well above 100 per cent. China makes more than 80 per cent of the world's solar panels.

The tariffs could slow global trade and economic activity. Carbon dioxide emissions dropped during the COVID-19 pandemic in 2020 and during the global financial crisis in 2009, then rebounded within a year.

Jackson said he expects at most a 1 per cent drop in emissions if full tariffs are implemented — significant, but far less than the 5.7 per cent that his group calculated for the pandemic's first year.

And Jackson noted that the world can't reach net-zero carbon emissions to try to limit future warming without structural changes, namely replacing fossil energy and manufacturing with clean renewable energy.

“A drop in emissions is important. But it boomerangs back to the same levels or keeps increasing afterwards,” he said. “And we really haven't done anything meaningful to address climate issues.” Michael Gerrard, director of the Sabin Centre for Climate Change Law at Columbia University, also thinks there could be a slight, temporary drop in greenhouse gas emissions if tariffs paralyse businesses and people aren't working.

But, he said, the higher prices for components for new renewable energy facilities will make some not economical to build and there will be far fewer imports of electric vehicles, both of which will lead to more emissions.

The transition to electric vehicles is an important part of the shift to clean energy to reduce emissions from road transport. The United States is a top importer of EVs and China is a top exporter.

Renewable energy investor Excelsior Energy Capital announced Tuesday that it has raised just over USD 1 billion to continue investing equity in solar, energy storage, wind and other energy transition projects across the United States.

Co-founder and managing partner Chris Moakley said they need stability and predictable costs — tariffs cause volatility.

“If there is an increase in tariffs, I think there's going to be a time where we will have a slowdown,” he said. “The overall economics of these investments and transactions ... there's going to need to be a reset.” Grid-scale batteries and solar panels, as well as power transformers, are among the hardest hit by price increases on imports, said David Shepheard, partner and energy expert at the global consultant Baringa.

Combining batteries with green energy is a fast-growing climate solution. Batteries allow renewables to replace fossil fuels like oil, gas and coal, while keeping a steady flow of power when sources like wind and solar are not producing.

Shepheard calculated a 55 per cent price increase for grid-scale batteries if the tariffs are fully implemented on China, where about 80 per cent of these batteries are manufactured, undermining the case for using solar and battery storage to satisfy a surging demand for electricity.

If prices for renewables increase, the United States will turn more to fossil fuels, tying the nation to carbon-emitting power sources for decades, Shepheard added.

President Joe Biden sought to lock in a trajectory for reducing the nation's greenhouse gas emissions. Trump began reversing the country's energy policies his first day in office with a spate of executive orders aimed at boosting oil, gas and coal.

He's also moved aggressively against clean energy technologies, including halting offshore wind lease sales in federal waters, cancelling clean energy loans and threatening action against states' climate laws. (AP) NPK NPK