Since the 1960s our scientists have worked with NOAA researchers to study the ozone layer.
We use a combination of satellite, aircraft and balloon measurements of the atmosphere.
The ozone layer acts like a sunscreen for Earth, blocking harmful ultraviolet, or UV, rays emitted by the Sun.
In 1985, scientists first reported a hole forming in the ozone layer over Antarctica. It formed over Antarctica because the Earth’s atmospheric circulation traps air over Antarctica. This air contains chlorine released from the CFCs and thus it rapidly depletes the ozone.
Because colder temperatures speed up the process of CFCs breaking up and releasing chlorine more quickly, the ozone hole fluctuates with temperature. The hole shrinks during the warmer summer months and grows larger during the southern winter. In September 2006, the ozone hole reached a record large extent.
But things have been improving in the 30 years since the Montreal Protocol. Thanks to the agreement, the concentration of CFCs in the atmosphere has been decreasing, and the ozone hole maximum has been smaller since 2006’s record.
That being said, the ozone hole still exists and fluctuates depending on temperature because CFCs have very long lifetimes. So, they still exist in our atmosphere and continue to deplete the ozone layer.
To get a view of what the ozone hole would have looked like if the world had not come to the agreement to limit CFCs, our scientists developed computer models. These show that by 2065, much of Earth would have had almost no ozone layer at all.
Luckily, the Montreal Protocol exists, and we’ve managed to save our protective ozone layer. Looking into the future, our scientists project that by 2065, the ozone hole will have returned to the same size it was thirty years ago.
Scientists suspect that the 2015-2016 El Niño – one of the largest on record – was responsible. El Niño is a cyclical warming pattern of ocean circulation in the Pacific Ocean that affects weather all over the world. Before OCO-2, we didn’t have enough data to understand exactly how El Nino played a part.
Analyzing the first 28 months of data from our Orbiting Carbon Observatory (OCO-2) satellite, researchers conclude that impacts of El Niño-related heat and drought occurring in the tropical regions of South America, Africa and Indonesia were responsible for the record spike in global carbon dioxide.
These three tropical regions released 2.5 gigatons more carbon into the atmosphere than they did in 2011. This extra carbon dioxide explains the difference in atmospheric carbon dioxide growth rates between 2011 and the peak years of 2015-16.
In 2015 and 2016, OCO-2 recorded atmospheric carbon dioxide increases that were 50% larger than the average increase seen in recent years preceding these observations.
In eastern and southern tropical South America, including the Amazon rainforest, severe drought spurred by El Niño made 2015 the driest year in the past 30 years. Temperatures were also higher than normal. These drier and hotter conditions stressed vegetation and reduced photosynthesis, meaning trees and plants absorbed less carbon from the atmosphere. The effect was to increase the net amount of carbon released into the atmosphere.
In contrast, rainfall in tropical Africa was at normal levels, but ecosystems endured hotter-than-normal temperatures. Dead trees and plants decomposed more, resulting in more carbon being released into the atmosphere.
Meanwhile, tropical Asia had the second-driest year in the past 30 years. Its increased carbon release, primarily from Indonesia, was mainly due to increased peat and forest fires - also measured by satellites.
We knew El Niños were one factor in these variations, but until now we didn’t understand, at the scale of these regions, what the most important processes were. OCO-2’s geographic coverage and data density are allowing us to study each region separately.
Why does the amount of carbon dioxide in our atmosphere matter?
The concentration of carbon dioxide in Earth’s atmosphere is constantly changing. It changes from season to season as plants grow and die, with higher concentrations in the winter and lower amounts in the summer. Annually averaged atmospheric carbon dioxide concentrations have generally increased year over year since the 1800s – the start of the widespread Industrial Revolution. Before then, Earth’s atmosphere naturally contained about 595 gigatons of carbon in the form of carbon dioxide. Currently, that number is 850 gigatons.
Carbon dioxide is a greenhouse gas, which means that it can trap heat. Since greenhouse gas is the principal human-produced driver of climate change, better understanding how it moves through the Earth system at regional scales and how it changes over time are important aspects to monitor.
The First Climate Model Turns 50, And Predicted Global Warming Almost Perfectly
“The big advance of Manabe and Wetherald’s work was to model not just the feedbacks but the interrelationships between the different components that contribute to the Earth’s temperature. As the atmospheric contents change, so do both the absolute and relative humidity, which impacts cloud cover, water vapor content and cycling/convection of the atmosphere. What they found is that if you start with a stable initial state – roughly what Earth experienced for thousands of years prior to the start of the industrial revolution – you can tinker with one component (like CO2) and model how everything else evolves.”
In 1967, a groundbreaking paper in climate science was published, detailing the inputs and feedbacks for the first accurate climate model. You don’t have to look far to find contentions that climate models are wrong, inaccurate and unreliable: 8 of the first 10 results on google state it. Yet if you look at the science, the original model, even at age 50, does a remarkable job of getting things right. The biggest success? Understanding how large-scale processes work, including the thermodynamic effects of adding additional greenhouse gases to Earth’s atmosphere. The increase of temperature – approximately 2 degrees C for a doubling of CO2 – was well known then, and continues to be well known today. There are uncertainties and difficulties in modern models, but that doesn’t mean there’s uncertainty surrounding global warming. Quite to the contrary, the evidence has never been better.
Does Kara have a period? I mean, I don’t know how Kryptonian bodies work or if their internal organs are the same as ours or if they have uteri or testes or how their reproduction even works but do you think that Kara learned that periods were a thing on earth for people with uteri and planned out one week a month in which to pretend she had cramps and allowed herself to be a little extra moody and always carried around tampons and pads, so that she could give them to people whenever they asked if anybody had any extras? Do you think that she kept a bottle of Motrin in her backpack, despite the fact that she had no use for it, and offered one up every time a classmate complained about cramps or migraines?
Do you think she got really confused at Playtex commercials because “Alex, why don’t you ever run down the beach when you’re menstruating? Why is that liquid blue? Is that what menstrual blood looks like? Alex, why are you laughing?”