Climate Corner
Montana Climate Matters: An Introduction
Hey savvy news reader! Thanks for choosing local.
You are now reading
1 of 3 free articles.
To provide a better understanding of what climate change means for Montanans, we are hosting a new monthly series, entitled Montana Climate Matters. Each month, you’ll hear from experts knowledgeable about climate science, impacts, and solutions. Our goal in this endeavor is to facilitate understanding, promote discussion, and help provide a roadmap for action on this critical issue. We hope you’ll follow the series and consider it an opportunity to stay informed.
We’re taught in school that climate is the long-term trend in weather as it is measured and understood over years and decades. Weather, on the other hand, is the hourly, daily, or weekly ups and downs in temperature, precipitation, atmospheric pressure, wind, humidity, and cloud cover. I think of the difference between climate and weather as the clothes in my closet. What I choose to wear on a particular day is dictated by weather. All the clothes in my closet, which would certainly be different if I lived in Hawaii, is determined by the climate.
The National Atmospheric and Oceanic Administration (NOAA) is the source for climate and weather information. NOAA reports climate in reference to the 30-year average of the weather station data for a particular location. This average period is called the “climate “normal”. The current climate normal spans the period from 1991-2020, but every decade, “normal” gets bumped ahead 10 years. For example, when we released the Montana Climate Assessment (http://montanaclimate.org) in 2017, the climate normal was the period from 1981-2010. Not everyone likes the idea of shifting the reporting baseline, and it’s important to remember that recent 30-year climate averages are anything but normal when looking at long-term trends.
Climate change has occurred throughout geologic time. For example, Montana was oppressively warm when dinosaurs roamed the region and significantly colder during the ice ages. Nonetheless, the cause and rate of current warming is something new, and it’s due to increased greenhouse gases (carbon dioxide, methane, nitrous oxide, and ozone) in the atmosphere from the burning of fossil fuels. The connection between increasing greenhouse gases and global warming has been understood by scientists for over 200 years, and today, 97% of climate scientists agree that humans are responsible. Globally, the Earth has warmed about 2oF since 1880, and an additional warming of 4-7oF is projected by the end of this century.
Montana is 2-3oF hotter now than in 1950, which equates to a rate of warming of about 0.2oF per decade. We have surpassed the temperature average of the Dust Bowl years, and 2015 was as warm as the warmest year (1934) ever recorded in Montana. In fact, our average temperature is now higher than any time since the last ice age, 20,000 years ago. Montana is warming faster than the nation as a whole, because of our location far from the moderating effects of the ocean, our high altitude, and our northern position.
Montana’s temperatures will continue to rise until we curb greenhouse gas emissions. This warming threatens our snowpack and glaciers, water supplies, food production, forests, and wildlife, not to mention our health and livelihoods. NOAA reports that our most costly weather/climate disasters have been the run of droughts and wildfires that we’ve experienced since 2000, mostly notably the flash drought of 2017. We’re continually surprised by record spring floods, statewide droughts, large wildfires, and suffocating wildfire smoke, but more of these events are likely in the coming decades.
In the next column, we will explore Montana’s changing climate in more detail.
Cathy Whitlock is Regents Professor Emerita of Earth Science at Montana State University and lead author of the 2017 Montana Climate Assessment.
