• A year after the coronavirus pandemic shuttered businesses and grounded flights across the world, scientists say the resulting temporary drop in carbon emissions has had no lasting impact on climate change.
• In fact, many metrics of the planet's health declined significantly last year, according to the National Oceanic and Atmospheric Administration's new "State of the Climate in 2020" report.
• 2020 saw the highest concentration of greenhouse gases in Earth's atmosphere ever recorded, along with unprecedented global sea levels and average global temperatures.

A year after the coronavirus pandemic shuttered businesses, grounded flights and reduced vehicle traffic across the world, scientists say the resulting temporary drop in carbon emissions has had no lasting impact on climate change.

In fact, many metrics of the planet's health declined significantly last year, according to the National Oceanic and Atmospheric Administration's new "State of the Climate in 2020" report.

The NOAA's report, published in the Bulletin of the American Meteorological Society, confirms that despite a 6% to 7% drop in emissions from reduced activity amid the pandemic, the concentration of greenhouse gases in Earth's atmosphere still hit its highest level ever recorded last year.

Scientists also confirmed other records in 2020, which include:

• The highest annual increase in concentrations of methane, a potent climate-changing gas
• Average global surface temperatures were among the hottest on record
• Sea levels reached the highest on record
• Oceans absorbed a record level of carbon dioxide
• 2020 was the hottest year on record that did not feature an El Niño.

The findings come shortly after a stark analysis from the United Nations Intergovernmental Panel on Climate Change, which warned that limiting global warming to close to 1.5 degrees Celsius or even 2 degrees Celsius above pre-industrial levels will be impossible in the next two decades without immediate widespread reductions in greenhouse gas pollution.

The annual global average carbon dioxide concentration at Earth's surface was 412.5 parts per million, roughly 2.5 ppm more than in 2019, the highest in at least the last 800,000 years, the NOAA report said.

Last year also saw a record spike in emissions of methane, which remains in the atmosphere for a shorter amount of time than carbon dioxide but delivers roughly 84 times as much warming in that period.

Hotter-than-average temperatures were widespread across the world last year. In Europe, 2020 was the hottest year on record, with all five of the warmest years occurring since 2014, the report said.

The average surface air temperature over land in the Arctic last year was the highest ever recorded in the last 121 years. The Arctic also experienced its highest wildfire year in 2020.

In central Siberia, where the majority of wildfires burned, record high spring temperatures triggered rapid snowmelt that contributed to the fourth-smallest snow cover extent in May for the continent and record smallest in June, according to the report.

The U.S. also saw a record number of costly disasters in 2020 as climate change triggers more frequent and intense hurricanes, wildfires and floods.

The country had a total of 22 climate disasters that each cost more than $1 billion, shattering a previous annual record of 16 disasters the country saw in both 2011 and 2017, the report said. Wildfires in the Western U.S. also burned nearly 10.3 million acres from California to Colorado, the most the country has seen in over two decades.

Looking ahead, 2021 has already surpassed some of last year's records.

July marked the hottest month ever recorded. And a heatwave that scientists declared was made "virtually impossible" without climate change hit the Pacific Northwest and Canada, resulting in hundreds of heat-related deaths.