As I write this blog today (8/16/2020, Seattle, WA), the weather app on my phone is telling me it’s 98°F outside. The U.S. weather service is saying 95°F. Either way, that’s pretty damn warm. I start to melt when the temps get into the 80s! But I suppose I shouldn’t complain. All across the west, we are seeing temperatures maxing out in the high 90s and even 100s! Here is the map showing current temperatures across the U.S. for today, August 16, 2020.
So why is it so hot? A weather man would tell us it’s summer, the sun’s rays are pointed straight at us. The days are long and there is a big ridge of high pressure over the west today that’s giving low winds and cloud-free conditions. The perfect storm for high temperatures. But I can’t help asking whether it has always been this warm? I’ve lived in Seattle about 30 years and I sure don’t remember so many hot days! All indications are that 2019 was one of the hottest years on record and the summer of 2020 will probably be the hottest summer in recorded history across the U.S.
So I wanted to see if my perceptions were true or not. Is it really getting hotter in Seattle? Here is data I obtained from the NOAA Climate Data Online site for Seattle Tacoma International Airport.
So is this evidence for global warming. Absolutely! But there is another phenomena that contributes to warming called the urban heat island. As cities grow, they have more pavement and less vegetation and the concrete holds more heat and causes the surrounding areas to warm. While it can be a little complicated to separate out the effects from global warming and from the urban heat island, there are a number of ways to do it. The easiest is to look at the temperature trends in a city and in a nearby (smaller) community. Here are some good sources on the urban heat island effect:
Either way, though, the trends observed are what we experience, regardless of how much is due to greenhouse gases and how much is due to the urban heat island effect.
Next, I want to show how easy it is to generate these plots for anywhere in the U.S. or even the world.
This is a great exercise for students at the middle or high school level.
First, you can get the data from the NOAA Climate Data Online site.
This site has thousands of sites around the country and around the world, although sometimes it can be tricky to find what you are looking for…. Here are my directions for the easiest way to find the data for your location.
After going to the main location, choose “Search Tool”
Select Weather Observation Type/Dataset
Choose “Daily summaries”
Enter the dates you want to get data for and then in the search box, type the names of different cities or locations. Hit search and you will get a map of all sites that were found. Check the dates carefully! Many sites will not have long-term data. Once you find the site you want, add it to your cart. You can add more data sites to your cart or stop there. Once you are ready proceed to your cart. (Just like Amazon!). For the Phoenix area, I found the Phoenix Airport ( PHOENIX AIRPORT, AZ US. Station ID: GHCND:USW00023183) to have data going back to 1933! Wow. So that’s the site I’ll use.
For “Output format” choose “Custom GHCN-Daily CSV”. Check your dates again and hit continue. You’re almost done! Now you can check any fields of data that you want. Important: Be sure to click on “Air temperature” or you might end up with no data! Usually you can get the daily average, min, and max temperature in °F. Hit continue one more time… Check your request for the last time, add your email address and hit “Submit order”.
At this point you will get two emails. The first simply tells you that you have submitted the request and it’s being worked on. The second email tells you the request is complete and how to get your data. Usually it takes anywhere from minutes to a few hours to get the data. I just this did on a Sunday and got the data back in less than 3 minutes…!
Since I just requested the Phoenix data, let’s take a look.
I started by looking at days per year over 90°F. That was dumb. It’s like always over 90°F there!
So let’s try days per year over 100°F and 110°F (that’s hot!)
I just checked and it’s 113oF in Phoenix today!
On Sunday, it was 130oF in Death Valley, probably a new record for the hottest temperature ever anywhere on earth!
Among scientists, there is no debate about global warming. That’s a made up “debate” by people who have a vested interest to obscure the truth. We have very good physical understanding of how CO2 affects the earth’s climate, where CO2 and other greenhouse gases come from, and what are the current impacts. There are many, many pieces of evidence to support this (temperature changes, loss of glaciers and Arctic sea ice, biological changes, etc.). I will describe the overwhelming evidence for you in a future blog post. The big issue is that if we keep releasing greenhouse gases, it will keep getting hotter.
What is really amazing is that during one of the hottest summers on record in the U.S., the EPA just announced it is relaxing the rules on fossil fuel companies to allow them to release more methane, of one of the strongest greenhouse gases. Unbelievable:
In a future blog post, I will describe more on the basics of global warming, the overwhelming evidence showing that we are experiencing unprecedented warming now, and what we can do about it.