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Chat Transcript: How Does NASA Study Earth's Climate?
This color-coded map displays a long term progression of changing global surface temperatures anomalies.This color-coded map displays a long term progression of changing global surface temperatures anomalies. Image credit: NASA
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NASA/JPL atmospheric scientist Mike GunsonNASA/JPL atmospheric scientist Mike Gunson will answer questions during a live chat. Image credit: NASA/JPL
NASA celebrated Earth Day with a live Web chat on Apr. 22, 2010. Mike Gunson, JPL project scientist for NASA's Orbiting Carbon Observatory-2 mission, answered questions that ranged from volcanoes to the climate and greenhouse gases. Here is the full transcript.

Jason (moderator): The NASA Earth Day chat is now open. My name is Mike Gunson. I am a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and I will be taking your questions today. I am the lead scientist on a mission called NASA's Orbiting Carbon Observatory-2. It is a mission that will launch in a few years and study Earth’s atmosphere. So let's get started. We really want to hear from students and teachers.

To ask a question, please type out your question below and hit the "Ask" button on the right. This is a moderated chat. We're answering questions as soon as possible. Many thanks for your patience.

Mike Gunson: We got these email questions from Ms. Calkin's 4th grade class at the Captain Samuel Douglass Academy in Brookline, New Hampshire.
1. Will Earth ever end? - Morgan
Scientists dont think the Earth will end any time soon. It may end when the sun dies millions of years from now.

2. Have you ever been to another planet? - Carolyn
No but as a big fan of Star Trek and other science fiction stories, I sure wish I could!

3. Why is the sky blue? - Joshua
Great question. This is the blue from sunlight scattered by individual air molecules in the Earths atmosphere. The sunlight is hitting a molecule and, something like a ball bouncing off an object, it is being redirected all around, including back into your eyes when you look up. Sometimes on a bright moonlight night, the sky will also appear faintly blue for the same reason. Technically, it is described as Rayleigh scattering after Lord Rayleigh the English physicist.

4. What do you have to do to get a job with NASA? - Zac
NASA and JPL are always looking for bright enthusiastic young scientists and engineers. Most, if not everyone, have started by doing well in school at math and science before going to university or college to complete a degree in science or engineering.

5. Do astronauts recycle when they are in space? - Emily
Don't know but I'd sure like to know.

6. If you cross lines between Earth and the atmosphere, do you get shot backward hurling to Earth? - Nick
Not sure I understand the question.

7. Is there life on any other planets? - Ryan
We don't know for sure but there are a lot of scientists looking!! So far they have found evidence of Earth-like planets but no direct signs of life beyond our own planet.

8. How many years of college does it take to get into NASA? - Clement
Most scientists and engineers have completed a degree at university or college over 4 years, some, like myself have gone on for another degree over another 4 years or so.

9. Do you always know the exact answer to everything? - Devin
NO!! But that sometimes does not stop me guessing ... (My son and wife hate that).

10. What do YOU at home and at work to help the Earth? - Livie
I am trying hard to reduce my carbon footprint by driving a hybrid car and I have installed solar panels for electricity at home. (Makes great use of the California sunshine.) I try to recycle as much as possible too.

11. When you were in 4th grade, what was your dream? To be in NASA? - Livie
Growing up in England, I never dreamed of working in the United States never mind NASA. I have to admit that I remember wanting to work on trains (steam engines) like my grandfather but nothing more. I am probably one of those people who just got lucky and ended up with a dream job without planning on it!! It can happen to you too if you do well at school. Good grades will open many doors and give you the opportunity to do anything you want.

12. When you look at the Earth from space, can you see any improvement, or is it still getting worse? - Megan C
If we look with human eyes, as astronauts do, I think it would be hard to say yes or no. Through the eyes of the instruments we have built to study the Earth and flown on satellites, it clearly is not getting better and indeed most scientists would say it is worse.

13. Do satellites run on batteries? - Megan B
Yes (and no). All satellites need some way to generate electricity such as solar panels, just like the ones I use on my home, but nearly all satellites use batteries to store the electricity to use when there is no sunlight.

14. Does pollution and littering on Earth effect outer space? - Shannon
Not that we know. Gravity keeps it here on Earth.

Warner_Elementary: Just want to say hello from Warner Elementary in SD! :)

Mike Gunson: Go ahead and ask a question!

earthday: hi Mike .. what exactly is earth day... what is is done by NASA on this day...

Mike Gunson: In the words of President Obama today, Earth Day is about one of the greatest challenges of our time, caring for our planet. Earth Day began as a national "environmental teach-in" in the fall of 1969.

jsherry: The 6th graders are here from Kickapoo Middle School in Viola, Wisconsin too!

Mike Gunson: Nice to see you here. Do you have a question?

A student from India named Akarsh emailed these questions:
1. What are the new preventive measures which NASA is going to take in controlling Earth's climate in this decade?
NASA is funded as a research agency and does not have responsibility for corrective actions. However, more importantly, controlling the climate is a huge and very uncertain thing which could have unexpected consequences. There have been some studies but nothing is planned. The best approach is preventive action by reducing and eliminating emissions of greenhouse gases such as carbon dioxide.

2. According to your Study of Climate, is there any change in the climate over the past decade?
Yes. Global temperatures have risen over the past several decades, and some of the hottest years in recorded history have been since 2000. More obviously, the Arctic polar ice sheet has covered a smaller area during each summer, and the larger land glaciers are melting more quickly and disappearing.

3. Does Earth have the ability to absorb Carbon dioxide?
Yes in the ocean and in the forests. Over the long term, carbon dioxide is absorbed and lost from the atmosphere only by the ocean and stored in the deepest ocean. But this takes (at current rates) hundreds of years.

4. Can this cause more extinctions in nature?
Yes. The changing climate has led to warmer temperatures changing the habitat range of plants and animals. In California, a small mountain mammal, the pika, has been seen to be moving to higher ranges where the temperatures are cooler and could run out of habitat ( I recall comments in studies by biologists that climate change is causing habitat change faster than many species can move or adapt. In the oceans, increasing adsorption of carbon dioxide has caused changes in the ocean’s acidity on top of increasing temperatures, both impacting small zooplankton and phytoplankton.

5. Can these Carbon be transformed into any other heavenly body?
I am not sure I understand the question, but carbon dioxide is very stable and inert in the atmosphere.

6. What is the main aim of Orbiting Carbon Observatory?
To measure the distribution in the Earth’s atmosphere of carbon dioxide from which scientists will be able to learn more about the role of human and natural sources of carbon dioxide as well as the distribution of places which absorb carbon dioxide from the atmosphere.

Jason (moderator): To ask a question, please type out your question below and hit the "Ask" button on the right. This is a moderated chat. We're answering questions as soon as possible. Many thanks for your patience.

ASpirasouth: Is there any other positions other than becoming an astronaut to work for NASA available?From aspira south in Homestead fl

Mike Gunson: Yes, NASA has tens of thousands of engineers, scientists and every kind of job or position. It helps if you have an interest in space exploration and Earth science. It takes a lot of different types of people to make NASA work!

Philliph: What do an mechanical engineer do in this kind of work?

Mike Gunson: Many mechanical engineers help in the design and building of satellites, spacecraft and instruments for NASA. If you are a student, visit the engineering department at your local college and they can tell you more.

SeaOtterScientists: Hello from Fleming Island Elementary. We have a few questions. Our first question is Will the volcano effect us in anyway? If yes what do you predict will happen?

Mike Gunson: Hello Fleming. Besides the impact to air travel, volcanoes like the one in Iceland eject a large amount of ash and sulfur into the atmosphere. These form particles (aerosols) which reflect sunlight back out to space and lead to cooling. A really, really large eruption like Mt. Pinatubo in the earlier 1990s can cool the whole planet.

Jason (moderator): We've had some great questions so far. Please keep sending them in! Just type out your question below and hit the "Ask" button on the right.

cfunky: How can you determine what next year's temps might be?

Mike Gunson: Really good question that many people would like an answer to. The best we can do is predict general trends but just like weather forecasting it's very difficult to be very specific over such a long time. In this past winter, the El Nino condition in the Pacific led to very different weather patterns throughout most of the world.

SeaOtterScientists: John from Ms. Soszynski's class asked: How much has the climate changed from 2000?

Mike Gunson: If you go to our Web site at you can find a lot of graphs and information on changes since 2000. Temperature change globally worldwide seems to be about 0.2 degrees Centigrade warmer since 2000.

Philliph: Can our planet survive if we keep doing the things we do at the same rithim?

Mike Gunson: Most predictions show a much, much warmer world if we continue releasing greenhouse gases at the current rates.

manud: can the earth live for another 100 years , keeping in mind the amount of harm full gases being evolved , how nasa is helping the earth ?

Mike Gunson: Well the Earth will still be around probably but it may be very very different. It could be 2 or 3 degrees warmer on average, sea levels could be considerably higher. But there is a great deal of uncertainty as to the exact changes which will occur. NASA is helping by research and studies using satellite measurements to understand these changes.

aaron: Hi Mike, Aaron here from the Philippines. Which parts of the globe are hardest-hit by global warming? Cos I read somewhere that there are parts of the globe where the ozone layer has holes and such.

Mike Gunson: The biggest effects have been seen in the northern regions and the Arctic where warmer temperatures have been recorded and we see less polar sea ice in the summer and it appears to be getting thinner.

Jason (moderator): We've had some great questions so far. Please keep sending them in! Just type out your question below and hit the "Ask" button on the right.

zahni: Hello Mike! Greetings from Germany... What do you think of the IPCC?

Mike Gunson: I think the IPCC is an exhaustive summary of current scientific research and findings. Thousands of scientists from around the world, including many of my colleagues within NASA, contributed to the reportts. Many scientists are already working and planning for the next report.

Jason (moderator): Just remember that this is a moderated chat. We're answering questions as soon as possible. Many thanks for your patience.

Cindy: My son's school would love to participate in one of these chats...will you be doing another one?? Where can we find out ahead of time so they can plan classroom wide interaction?

Jason (moderator): We hold these chats at least once or twice a month on a wide range of subjects. To find out when chats are scheduled, check out the NASA Chat page at As soon as we schedule a chat, we post it on that page. Additionally, we Tweet it on the @NASA twitter account availabe at

Warner_Elementary: If there is global warming, why was our winter one of our worst ever?

Mike Gunson: Really good question. It may be surprising but overall around the world this was one of the warmest Januarys on record. But locally in different areas the El Nino in the Pacific resulted in a shift in the Jet Stream in the northern hemisphere which led to a wet winter in California and lots of cold weather and snow in Washington, DC, and similarly snow and cold weather in England and in northwestern Europe. This is one of the differences between weather and climate. Weather at one place and time can be quite different than the overall trend in climate.

ileana95: How does the JPL work with other organizations to help predict the climate over the next years?

Mike Gunson: We at JPL have design and build many instruments to study the Earth from space. These are used to help improve our understanding of how the Earth works and then in collaboration with other scientists, improve climate predictions.

Warner_Elementary: What will happen to the earth if we don't stop polluting?

Mike Gunson: Our best predictions show the Earth warming up by several degrees over the next hundred years from continued build up of greenhouse gases in the atmosphere. Sea levels will continue to rise as the oceans warm up and the great land glaciers (Greenland, Antarctica and elsewhere) melt.

icarusfactor: How is the carbon level parts per million number gathered and how often is that number updated?

Mike Gunson: There are a number of methods used to measure the concentration of carbon dioxide in the atmosphere. There is a network of stations around the world where samples of the air are gathered on a daily and weekly basis. These are returned to laboratories here in the U.S. to be carefully analyzed for the amount of carbon dioxide in the atmospehre. We at NASA have and are developing ways of measuring the concentration of carbon dioxide in the atmosphere from space. One of these is the experiment I am working on right now, the Orbiting Carbon Observatory-2, which we hope to launch no later than Feb. 2013.

Jason (moderator): We really appreciate all the great questions we are getting. We may not be able to get to all of them but we are trying! Please keep sending them in. Just type out your question below and hit the "Ask" button on the right.

Philliph: Are not we too late to start doing something for our planet or there is time yet?

Mike Gunson: No, I believe we can do something! But it would require cooperation and action by everyone in the world. Obviously this has to be done fairly. These are part of the considerations in the international climate discussions that are currently underway.

calif_cougar: Are our summers going to get hotter?

Mike Gunson: Very likely, based on the climate model predictions.

manud: are the measurements taken by NASA made public , if yes ? can we get its link ?

Mike Gunson: All NASA data is public. There is a lot of it. It's held in many data repositories. Best place to start is at We will give a few more urls at the end of this chat.

Jason (moderator): A great list of data resources is available here:

Warner_Elementary: Do you at NASA need special cameras to study earth from sattelights?

Mike Gunson: We at NASA use many different instruments including cameras, altimeters, radars and laser (LIDAR) which use almost every part of the electromagnetic spectrum, to "see" different parts of the Earth's surace, ocean and atmosphere.

SeaOtterScientists: Payton: "My teacher says that the population has effected our Earth." Can you explain more?

Mike Gunson: As the Earth's population has grown, we use more water, we need more land to grow food and to build houses. We use more fuels for energy to heat our homes, cook our food, move around and build everything we need on a day-to-day basis. In some parts of the world, we have run out of some of our basic resources. My area of research is in how our use of fuels is affecting the build-up of greenhouse gases in the Earth's atmosphere.

ileana95: what exactly happens in the ocean currents when ice melting?

Mike Gunson: The overall ocean circulation comes about from differences in temperature and salinity between different regions. When large quantities of ice melt, this can affect both the temperature and salinity of ocean water. For example, melt water from Greenland pours out into the north Atlantic so some scientists have been trying to understand if this would affect the Gulf Stream. To help better model ocean circulation, NASA is planning a new set of measurements of ocean salinity from space with the Aquarius/SAC-D mission, which we are working on with the Argentine Space Agency.

Jason (moderator): We really appreciate all the great questions we are getting. We may not be able to get to all of them but we are trying! At the end of the chat we will post some useful links about Earth and global climate change.


Mike Gunson: We don't see climate affecting the number of earthquakes or volcanic eruptions, nor is global warming enough to significantly affect the Earth's core temperature, large volcanic eruptions can have a global cooling effect.

manud: by how many percentage the annual carbon dioxide is increasing and how long do we have before it crosses allarming states ?

Mike Gunson: Today, the annual increase in carbon dioxide levels is about 2 parts per million out of 385. There is a great deal of debate as to what is an "alarming state." This could mean different things to different people.

We received these email questions from Ms. Ogden's sixth grade science class.
1. Ross - What recommendations would you make for new construction to aid in reducing global warming?
Many buildings are now constructed with energy conservation in mind. In California where I live, this can include wall insulation, double glazed windows, more shade over windows (from overhanging roofs for example), insulation in the attic, including solar panels in the building design, changing roofing materials, and I am sure there are many other ideas. These can make a big difference to the amount of cooling and heating you then need.

2. Ryan - What would happen if the carbon dioxide in the air went too low?
As far as we know over the past million year+C51s, there have been times in the ice ages where it has been as low as about a half of what is today. At this level, I don’t know if we can look back through fossils and tell if low carbon dioxide levels had a big impact as opposed to cooler temperatures. We do know that plant growth through photosynthesis requires carbon dioxide, and so with little or no carbon dioxide, I would be worried that plant growth would not be very vigorous.

3. Jamie - How much would biking to work help the environment?
Anything that stops us using gasoline in cars is a good thing both for the environment and getting exercise! (But stay safe!!)

4. Ilana - How is global warming going to affect us in the United States?
Most predictions show trends of warming temperatures and changes in precipitation patterns (both rain and snow). Out here in the west for example, this is very likely to affect how much snow falls in the mountains either because the snow falls as rain or because there is less generally. Most of our water for drinking, growing food, and hydroelectric power relies on the snow in the mountains, so this could be a big impact.

5. Harry - Will some regions have harsher winters?
Possibly. This past winter was pretty bad in the northeastern U.S. and in northwestern Europe, mainly due to a shift in the position of the jet stream. This in turn is associated with an El Nino condition in the Pacific Ocean. Some scientists believe that increased greenhouse gases may affect the wind patterns in the atmosphere (the general circulation) and could lead to changes in the frequency of cold winters in some regions just as we have experienced without an El Nino. However, I don’t think we can say this with certainty.

Jason (moderator): For everyone who wants to go back an see the questions that were answered already, we'll be posting a transcript of this chat within the next couple of business days. Check back on the site to find the transcript with the questions answered -- both in the chat and those e-mailed in.

Warner_Elementary: Is the hole in the ozone layer the cause of all earth's problems with global warming?

Mike Gunson: No. The ozone hole and loss of ozone in the ozone layer is caused by the release of chlorine-containing gases which are now regulated by international agreement. We have seen a slowdown in the rate of loss of ozone. It now appears that we have taken the right corrective action. There are some effects due to changes in ozone levels on the Earth's general circulation (wind patterns) but these are thought to be relatively small compared to the impact of continued build-up of greenhouse gases in the atmosphere. Interestingly, ozone is a greenhouse gas as well and when we find it in certain parts of the atmosphere.

icarusfactor: We have seen how many millions of sq kilometers of ice the arctic has lost over the years. I would like also to see how much thickness has been lost on average, do we know this number yet?

Mike Gunson: I am not sure of the exact numbers but we do know that the Arctic sea ice is generally newer and hence thinner. The older and thicker sea ice has been decreasing year to year. We are able to measure the age of ice by its roughness using radar from space.

earthday: what are these Grrenhouse gases... I see in my country they buit greenhouses for small plants...

Mike Gunson: The greenhouse effect refers to the trapping of radiation (heat) that would normally escape to space by gases and clouds in the atmosphere just like the glass walls of a greenhouse.Among the greenhouse gases are some which are made by human activities, even though the most important greenhouse gas is water vapor. Of those resulting from human activity, carbon dioxide is one of the most important.

Jason (moderator): Thanks very much for all the great questions. We have time for just a few more before we end this chat.

Mike Gunson: Thanks to you and everybody else whose had such great questions.

CHIMAPS: CHIMAPS INTERMEDIATE SCHOOL: Do satellites affect in any way our atmosphere or climate? Maybe satellites that have to be dispossed because they are too old or stop working.

Mike Gunson: No, not really even though they may appear relatively big, there are sufficiently few of them and they are small enough that they don't affect the climate. Every satellite project develops a plan for safe disposal when it stops working. Thanks CHIMPAS for staying with us!

Jason (moderator): We’ve had a great time answering your questions about Earth. Here are some useful links about climate change, JPL and NASA. So long from JPL in Pasadena, California.

Share how you and your family help our planet:
NASA’s Global Climate Change Web site:
A version for kids, called Climate Kids:
NASA's Earth page
JPL's Earth page
JPL Education