What NASA Knows from Decades of Earth System Observations

Summary

NASA's Earth science director, Karen St. Germain, discusses how the agency's 23 satellites monitor Earth's systems, revealing a 90 mm sea level rise since the 90s. She highlights the impact of greenhouse gases like carbon dioxide and methane, which trap heat in the oceans, causing melting Arctic ice, coastal flooding, and intensified hurricanes. The script emphasizes the urgency of climate change's effects on agriculture, wildfires, and global water cycles, showcasing NASA's predictive tools to aid decision-makers in addressing these challenges.

Takeaways

• 🛰️ NASA operates 23 satellites dedicated to observing Earth's systems, including the atmosphere, oceans, and land.
• 📈 Sea levels have risen an average of 90 mm since the early 1990s, according to sustained satellite observations.
• 🌱 Carbon dioxide is a critical greenhouse gas, primarily produced by burning fossil fuels, and accumulates in the atmosphere, especially during Northern Hemisphere winter months.
• 🐄 Methane, another potent greenhouse gas, is released from fossil fuel extraction, agriculture, and vegetation decay, but has a shorter atmospheric lifetime compared to carbon dioxide.
• ☀️ Greenhouse gases trap the Sun's energy, leading to increased global surface temperatures over land and ocean.
• 🌊 Approximately 94% of the extra heat trapped by greenhouse gases is absorbed by the oceans, which have a high heat capacity.
• 🧊 Arctic sea ice extent has been decreasing annually, affecting the reflection of the Sun's energy and contributing to global warming.
• 🏔️ Warming oceans erode land ice, such as glaciers, increasing the flow of ice into the oceans and contributing to sea level rise.
• 🏞️ Rising sea levels impact coastal communities and are exacerbated by phenomena like sunny day high-tide flooding.
• 🌱 Changes in the water cycle due to climate change result in wetter regions becoming wetter and drier regions becoming drier.
• 🌀 Intensified tropical storms and hurricanes are fueled by the heat trapped in the warming oceans, leading to more severe weather events.
• 🌾 Climate change affects agriculture by altering precipitation patterns and increasing temperatures, exacerbating drought conditions and impacting crop yields.
• 🔥 Prolonged wildfire seasons and more severe wildfires are observed, which not only damage ecosystems but also release more carbon dioxide into the atmosphere.
• 🌐 NASA's FIRMS tool and partnerships with organizations like the IPCC provide predictive capabilities and tools to inform decisions on climate change impacts globally.

Q & A

What is the primary role of NASA's Earth science directorate?

The primary role of NASA's Earth science directorate is to oversee the agency's efforts in understanding our home planet through the use of satellites that observe the Earth system, including the atmosphere, oceans, and land.

How many satellites does NASA currently have observing the Earth system?

NASA currently has 23 satellites observing the Earth system.

What significant measurement has NASA been able to make since 1993 with its satellites?

Since 1993, NASA has been able to make direct measurements of sea level height, observing an average rise of 90 mm.

What are the two major greenhouse gases discussed in the script, and how do they differ in their impact on the atmosphere?

The two major greenhouse gases discussed are carbon dioxide and methane. Carbon dioxide, produced from the burning of fossil fuels, accumulates in the atmosphere and lasts a very long time, while methane, produced from the extraction of fossil fuels, agriculture, and vegetation decay, is about 20 times more potent but has a much shorter atmospheric lifetime of around a decade.

Why is the trapped heat in the Earth system primarily found in the oceans?

The trapped heat is primarily found in the oceans because water has an enormous heat capacity, meaning it can absorb a lot of heat before its temperature increases significantly.

What impact does the melting of Arctic sea ice have on the reflection of the Sun's energy?

The melting of Arctic sea ice reduces the Earth's ability to reflect the Sun's energy back into space, as ice is a great reflector of sunlight. With less ice, more energy is absorbed, contributing to further warming.

How does the warming ocean affect land ice and contribute to sea level rise?

The warming ocean erodes the underside of glaciers, causing them to thin and eventually break off. This increases the flow of ice from land into the ocean, contributing to sea level rise.

What is the significance of sea level rise for coastal communities?

Sea level rise significantly impacts coastal communities by increasing the frequency and severity of sunny day high-tide flooding and exacerbating the effects of storms and other weather events.

How does climate change affect the water cycle and agricultural yields?

Climate change intensifies the water cycle, leading to wetter regions becoming even wetter and drier regions receiving even less moisture. This, combined with increasing temperatures, exacerbates drought conditions and negatively impacts agricultural yields around the world.

What tool does NASA use to identify and monitor fires around the world?

NASA uses the FIRMS tool, which utilizes high-resolution visible and infrared imagery to identify and monitor fires for decision-makers to understand fire locations and their duration.

How does NASA provide predictive capabilities for climate change impacts to communities and decision-makers?

NASA provides predictive capabilities through tools developed in partnership with the IPCC, allowing communities to locate their position on a map and view projections of sea level rise in their region, both in the present and into the future.