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Recently, two separate NASA studies
 illustrated the complex relationship

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between human activity and our atmosphere.

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First up, a team led by scientists
 at NASA's Jet Propulsion Laboratory

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focused on drops in nitrogen oxide
emissions during the COVID 19 lockdowns.

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Nitrogen oxide comes from sources
 like power plants and car exhaust

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and reacts to form surface level ozone,
 which is harmful to human health.

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Using NASA satellites, 

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the team saw that the lockdowns left
 a distinct 'fingerprint' on ozone levels

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in the lower atmosphere,
 which dropped about 2% globally.

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And while this may seem small,
 such a drop in harmful

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ozone would take about 15 years
 to achieve under even

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the most aggressive
 emission control scenarios.

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Interestingly enough, the team found that
 these drops were not uniform

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across the globe. 

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That where and when the lockdowns 

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occurred was very important in determining
 the impact on the atmosphere.

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Taking a look at these regions
 with blue representing below

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normal levels of ozone
 in the lower atmosphere,

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we could see that both Asia
 and the United States have

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a substantial impact
 on harmful global ozone levels.

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Factors like prevailing 

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winds, air temperature
 and moisture content all impact

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how efficiently ozone is produced
 and moves

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throughout the globe. 

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Like ozone, CO2 is a long lived gas
 that is easily

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transported through the atmosphere,
 which means that any changes in emissions

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is mixed with many different influences
 from both near and far.

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This makes it challenging to track
 and measure how local changes in

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human activity actually impact the levels
 of this greenhouse gas.

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Using NASA's OCO -2 instrument
 and the GEOS model, NASA

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researchers were able to spot short-term
 regional fluctuations in the atmosphere

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due to drops in human activity
 related to the lockdowns.

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This is the first time changes in CO2

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measurements have been tracked
 at such a scale all over the globe.

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The team's results 

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showed that the CO2 emissions dropped
 significantly in the Northern Hemisphere

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from February through
 May and rebounded during the summer

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when some restrictions eased. 

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The team 

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was also able to better distinguish
 which monthly CO2 fluctuations

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were due to human activities
 and which were due to natural causes,

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like the Australian wildfires
 and ocean circulation patterns.

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This is important because distinguishing
 between human and natural causes

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is a critical step towards measuring
 human activities' collective effects

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on CO2 emissions in near real time.

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The lockdown surrounding COVID 19
 were an unprecedented global event

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that highlighted the complex relationships
 between emissions and the atmosphere.

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By studying 

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these relationships, we can gain insights
 that could help us better design

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sustainable measures that can improve
 both human health and the climate.