Whizzing around the Earth at speeds of approx 17,500 miles per hour, and varying in size from a lunchbox to a school bus, are thousands of satellites. Working out the exact numbers seems to vary depending on how long satellites are meant to last (and my DuckDuckGo searches). SpaceWatch claimed in July 2024, there were 10,000 satellites orbiting the Earth. The UK Government shared in April 2024 there were over 9,000 satellites orbiting the Earth. At the time of writing, Orbiting Now told me there are 8,111 orbiting us. In short, there are lots of satellites and these numbers are set to increase – some reports suggest that by 2030 there could be more than 60,000 active satellites in space.
The first ever satellite was Sputnik 1 launched by Russia in 1957 and for decades satellites were very expensive and few in number with such projects led mainly by governments. This has all changed now. Falling down a satellite rabbit hole has revealed there is an emerging ‘space economy’ with private enterprises (yes, Elon’s SpaceX) and governments keen to launch satellites into space for all sorts of commercial and civic reasons. This huge increase in satellites is due mainly to reduced costs. To launch a satellite into a ‘low-Earth orbit’ (that’s 160 – 2,000km above Earth) the price has fallen from $65,000 per kilogram to $1,500 per kilogram—more than a 95 percent decrease. For context, in 2008, the European Space Agency’s Sentinel-3 earth observation satellite cost €305 million.
What do satellites have to do with climate change?
Anyway, I digress. I am exploring satellites because they have some incredible uses in the climate sector. We use satellites everyday for timekeeping, for GPS on our phone (fun fact, the EU’s GPS satellite is called Galileo) and for communication services in general. The government and military uses them for observation and intelligence gathering. Science uses Earth observation satellites to collect all sorts of data about the Earth and of course the reverse is true where many satellites collect data about space.
For example, in the EU, the European Earth Observation programme is called Copernicus. It has a family of 8 satellites, called sentinels, that measure data about the Earth, such as the air pollution, sea levels, and land use. All of the data from Copernicus is open source and free to use by anyone. Similarly NASA’s EarthData gives open access to NASA’s archive of Earth science data, which cover similar topics like the biosphere and climate indicators.
Data from satellites is being used by climate scientists and researchers all over the world to make evidence-informed decisions to help protect our planet. Search ‘satellites and climate change’ and you’ll get many articles explaining why satellites are superheroes in the climate fight, providing much needed data that will help us direct effective action. A report by World Economic Forum says by 2030, ‘Earth observation (EO) insights is projected to surpass $700 billion while directly contributing to the abatement of 2 gigatonnes of greenhouse gases annually’.
How satellites are helping to protect rainforests
On Climate Curious pod, we’ve had two guests share how they’re using satellite data to power up their climate work. A recent episode, How satellites are secret superheroes for rainforests, featured the amazing work by rainforests professor Dr. Jesús Aguirre Gutiérrez. Jesús explains that he works with researchers, Indigenous groups and local communities in rainforests to help protect the rainforests’ biodiversity. One of the challenges facing this kind of work is understanding if the data collected in one place can be extrapolated to another location or more widely.
“Is the same happening in the North of Mexico than in the South? Is the same happening in Brazil or in Africa? Right….those were kind of the questions that I had at the beginning. And I think one of the approaches… to answer some of these questions, to try to understand how biodiversity is responding to stress, or climate change, or land use changes is using satellite data.”
Using satellite imagery Jesús and his team are able to compare how forests are faring in different places but also across time as well – especially as one of the satellites, Landsat, has been around for 40 years!
“You can see how a place has changed through time, over the last year, the last 10 years, even the last 40 years. So that’s what I’m doing. I’m looking at how biodiversity changes in space, comparing locations, but also how it changes through time.”
These images are incredibly detailed – Jesús compares them to Google Earth – where you can zoom in on individual trees and medium-sized animals. Exploring an image’s ‘spectral signature’ also helps him learn how healthy a forest is, what kind of species a tree is, how many there are and where they are. In the past, for scientists to collect this kind of data, it would have been hugely labour intensive and limited in scope. But this isn’t only about data, Jesús shares, this work is also about supporting people.
“In the context of Brazil or Mexico, people live in these forested areas… and if they don’t have a way of making money from any other business, they are often faced with the position in which they can cut wood illegally to sell also to illegal buyers, perhaps, right?
This is happening a lot in Mexico, for instance, even in protected areas. These are huge areas, huge countries, in which perhaps policy implementation is not adequate or there’s not enough funding… If people need to live, then they’re going to have to do whatever’s necessary… If we address poverty, then… we have two wins. People aren’t living in poverty anymore, and we’re protecting the forest and the environment.”
By collecting and analysing data, scientists like Jesús, can help push for evidence-backed policies and actions, which can support both local communities, conservation efforts, the rainforests and our planet.
MethaneSAT: a special satellite to combat methane emissions
In another Climate Curious Episode, Why reducing methane is the ultimate climate hack, atmospheric scientist, Ilissa Ocko, explained how reducing methane could hit the brakes on climate change. Methane makes up about 1% pollution pumped into the atmosphere, but is actually far more dangerous – methane can warm 100 times more than the same amount of CO² of equal mass. Ilssa says cutting methane emissions is partly a ‘plumping problem’. By this, Ilssa is referring to how 40% of methane leaks occur when we extract, transport and heat oil, gas, or coal:
“It’s really easy to fix these leaks. The problem is, where are the leaks coming from? You know, they’re invisible? … We’re talking about big supply chains, kilometres of pipeline. We’ve been developing a lot of technologies over the past decades to be able to do this and one new technology… is this satellite called MethaneSAT. MethaneSAT can locate these leaks across the entire globe with unprecedented precision… it will tell us who’s responsible for leaks.”
Three years after Ilissa’s episode, in March 2024, MethaneSAT launched! You can view the free and fully accessible data here. Data analysis is already proving useful in showing that emissions in certain areas are significantly higher than those reported bottom-up estimates. The hope is this satellite will push polluters to fix their “plumbing problems” and hold them to account for these emissions.
These stories on Climate Curious are just two examples of why satellites are, well, simply, pretty awesome and a growing tool to help us in the climate fight. At Climate Curious, we know silver bullets don’t exist, but we love bringing to light powerful technological solutions that help both people and planet – and will continue keeping you up to date with them too!
Want to fall down the satellite rabbit hole too? Learn more:
– Listen to Jesús’s Climate quickie, How satellites spy on rainforests, for good
– Listen to Jesús’s full ep, How satellites are secret superheroes for rainforests
– Listen to Ilissa’s full ep, Why reducing methane is the ultimate climate hack
– Listen to more on methane and MethaneSAT, How methane ‘goggles’ are making pollution visible with methane scientist Daniel Zavala-Araiza.
– Learn more EU’s space programmes and Copernicus
– Learn more NASA’s Earth Observation Data
– Some interesting articles on satellites, How satellites revolutionised climate change science, and 6 ways satellites are helping to monitor our changing planet from space.
– See how many satellites are orbiting you right now
