Extreme weather and ocean events are increasing worldwide, largely due to human-induced climate change. But to fully understand these changes — and, in turn, predict when and where they will occur in the future — researchers and policymakers must also take naturally occurring climate change into account, new published research suggests. Nature communication Led by the University of Colorado Boulder.

Global sea levels have risen an average of 8 to 9 inches worldwide since 1880 due to human-caused global warming. But the amount of sea-level rise varies greatly from region to region; It changes with time such as high tide, low tide or storm.

Beyond that, sea levels also fluctuate due to year-to-year and decade-to-decade climate changes, such as El Niño. All of these different layers can challenge scientists to understand the primary cause of sea level changes in specific places at specific times.

Analyzing data from Indonesia’s Indian Ocean coast, scientists noted an increase in sea level extremes, or periods of high sea level, from 2010 to 2017. These events can cause flooding, soil erosion, saltwater contamination of water supplies, and other serious hazards. Problems of coastal dwellers.

The researchers found that sea-level rise extremes sometimes coincide with ocean heat waves, or periods of unusually high ocean temperatures.

Ocean heat waves can harm marine ecosystems, leading to consequences such as massive coral bleaching and the migration or die-off of fish. This affects individuals and businesses that rely on fish for food and livelihoods, and healthy reefs for protection from storm surges. Sea heat can also be a factor heavy rainThis will exacerbate flooding caused by sea-level rise.

When they occur together, sea-level rise and ocean warming can have more severe socio-economic and environmental impacts on coastal communities, so scientists were interested in understanding why sea-level rise and ocean heat waves are increasing. Coastal Indonesia.

“Although it is important to study sea-level rise and ocean heat waves individually, studying them together is scientifically important and socially relevant because the damage from these combined events can be much greater than if they occurred separately,” said lead author Weiqing Han. Professor of Atmospheric and Oceanic Sciences at CU Boulder.

To unravel the forces from 2010 to 2017, the researchers studied tide gauge and satellite data and conducted a series of modeling experiments. Although human-caused climate change is partly to blame, it is natural Climate changeHuman influence – which occurs regardless – has also played a role, the researchers concluded.

And during this particular eight-year period, human-caused climate change Natural climate change Reinforcing each other, the sea level rises. However, in other periods, natural climate change may counteract human-induced climate change, helping to slow sea-level rise.

Understanding the complex relationship between the two forces is essential to making accurate future predictions of extreme events, which affect long-term coastal development and management plans. This is especially important for developing countries, which may lack the resources to mitigate or respond to extreme events, making their residents more vulnerable.

“The study highlights the importance of improving the representation of natural climate change modes in our state-of-the-art climate models, and more accurately representing (human-caused) warming effects,” Hahn said.

Although previous research has focused on ocean heat waves sea ​​level Height increases over a period of days or weeks, and this is one of the first studies to explore those events in the context of major climate changes such as El Niño, Indian Ocean dipoles or Indian Niño.

“We wanted to weave together all the threads of this research Case study Indonesia is ground zero for the combined effects of El Niño and the Indian Ocean Dipole. Ocean heat waves “Higher sea levels will be pronounced,” said study co-author Michael McFadden, a senior scientist at the National Oceanic and Atmospheric Administration (NOAA).

Global temperatures are likely to rise further – and extreme weather And ocean events will continue to become more frequent and more intense—unless governments take steps to curb human-caused climate change, which researchers say includes reducing that. Greenhouse gas emissions From burning fossil fuels and limiting deforestation.

Wealthy and developed countries will need to make the biggest changes, the researchers argue. While countries such as the United States and China are responsible for large amounts of greenhouse gas emissions, developing countries such as Indonesia, which emit much smaller amounts of greenhouse gases, often bear the brunt of the effects of climate change.

“Climate change is real, dangerous and costly, especially for those least responsible for creating the situation we find ourselves in,” McFadden said.

“The good news is that when we are part of the problem, we can be part of the solution.”