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5 things you might not know about the sky

© Rod Mast

If you could drive your car straight up at highway speed, you’d leave the Earth’s atmosphere and enter space in just over an hour.

This thin, delicate band surrounding our planet makes life on Earth possible, yet the health of the atmosphere is being upended by fossil-fuel emissions — with increasingly perilous results. Earth’s atmosphere has more carbon in it now than it has had for 300 million years — with major implications for global climate.

Conservation International (CI) is giving voice to our beleaguered atmosphere with “Sky,” the latest film in the “Nature Is Speaking” series. Voiced by actress Joan Chen, the video calls attention to the state of our skies.

Here are a few things you might not know about the sky.

1. Could Earth become more like Venus? Let’s not find out.

Earth is the only planet in the solar system with an atmosphere that can sustain life as we know it. But it could have been very different — as evidenced by Venus. Superficially the closest planet to Earth in terms of size and proximity to the sun, the atmospheres of early Earth and Venus were not drastically different, yet today Earth is hospitable to life and Venus is a highly pressurized hotbox with an average daily temperature of around 460 degrees Celsius (860 degrees Fahrenheit). Scientists believe that the sun may have “cooked off” Venus’ water vapor, leaving only carbon dioxide — while the slightly cooler Earth retained its water (while hosting living organisms that consumed carbon and produced oxygen), enough to tip the scales to an atmosphere beneficial for life.

Now, humans are upsetting that delicate balance by pumping carbon dioxide into the atmosphere at an unprecedented pace, particularly over the last 50 years. The last time there was this much carbon in the atmosphere, humans didn’t exist. These CO2 levels are causing severe weather fluctuations, longer periods of drought and flooding, and more frequent and intense storms. While it’s unlikely that our planet could ever see an atmosphere like Venus, the history of our planetary neighbor is a cautionary tale to humans: Take care of your air.

2. Some scientists want to use giant space mirrors to fight climate change — but not everyone thinks this is a good idea.

Revolutionary climate engineering technologies might be the missing piece to the puzzle that can help us meet the climate goals outlined in the Paris Agreement. By the time the agreement goes into effect in 2020, the planet’s warming may have outpaced the plan to manage it. This has led some scientists to propose new — and sometimes polarizing — technologies, like artificial “trees” that would perform the same carbon-capturing duties as real trees. Another idea is solar radiation management technology, a type of climate engineering that reflects sunlight (and heat) back into space, thereby reducing the temperature on Earth.

Climate engineering technologies like this are meant to replace the services the atmosphere — and nature — provide for free. Yet, as their detractors point out, their benefits are limited. For example, giant space mirrors don’t address dangerous impacts of a warming climate, such as ocean acidification — only the warming itself.

Further Reading:

3. You’re not imagining it — it is getting harder to breathe.

You can thank climate change: The duration of seasons and more erratic weather patterns are causing plants to release more pollen into the air earlier and for longer periods. If you’re one of the lucky people who doesn’t currently suffer from seasonal allergies, that might change soon. The longer you’re exposed to an allergen (such as pollen floating around for an extended period), the more likely you are to develop sensitivity to it.

Although for most people allergies are a seasonal annoyance, air quality causes damaging health effects for millions around the world. Asthma rates have soared in the past decade due to air pollution and higher temperatures; today about 235 million people suffer from it worldwide, and over 80% of asthma deaths occur in low- and lower-middle income countries. Overall, the World Health Organization estimates that 3.7 million people die each year due to air pollution.

4. The eruption of one volcano can change the global temperature.

When volcanoes erupt, they spew particles and gases into the air, which have different effects. Ash and sulfur dioxide cause a cooling effect by reflecting sunlight away from the planet, while carbon dioxide causes warming by contributing to the greenhouse effect (trapping heat energy).

Some scientists believe that the Earth has maintained a relatively even climate for so long due to the heating and cooling caused by volcanic eruptions, going so far as to say climate change would be worse if not for the cooling episodes provided by certain eruptions. The effects are considerable: After Mount Pinatubo in the Philippines erupted in 1991, average global temperatures dropped about a degree Fahrenheit for two years; the 1815 eruption of Tambora in Indonesia brought a dip in temperatures that caused crop failures in North America and Europe.

5. Seeing through clouds = a win for science

The ability to scan Earth via satellite — known as “remote sensing” — has expanded considerably our understanding of climate, forests, farming and more. But for years, scientists in tropical regions were hampered by cloud cover, which obscured views from satellites and made precise monitoring and mapping of land difficult.

A relatively new open-source data platform that relies on old technology — radar — has changed all that, penetrating all weather conditions and returning high-resolution images and data.

For scientific organizations such as Conservation International, this tool is helping to illuminate land-cover change. With this technology, researchers are better able to observe when forests are cleared for farms and other uses in places such as Indonesia and Peru. Combined with optical satellite data (think Google Earth), scientists are able to get the full picture of what’s happening on the ground, then use the findings to inform conservation efforts and policy decisions.

Sophie Bertazzo is a staff writer at Conservation International.