Welcome to another post in our “Ask a Climate Expert” series where we address real-life questions that were sent to the Canadian Centre for Climate Services’ Support Desk. Here we are sharing our answers in an easy-to-understand format that is accessible to everyone, not just climate scientists.
As the planet heats up, Canadian professionals across all sectors are factoring climate data into their work. To prepare for climate change, they are considering future changes in climate variables such as precipitation, temperature, and more.
At the Support Desk, we respond to various inquiries from users related to accessing and understanding climate data. As users familiarize themselves with the data, it’s common to have questions. Today’s post focuses on guiding users through the process of reading the downloadable data files from ClimateData.ca.
Climate data on ClimateData.ca can be downloaded in several different file formats: CSVs, NetCDFs, JSONs, GeoJSONs, PDFs, and PNGs. Different formats are useful for different applications, and each file type has its own strengths and weaknesses.
In this blog post, we’re going to focus on how to read through the CSV format, since this is the most popular data format on ClimateData.ca. This is also a format that is readily accessible to most people.
CSV files, which stand for Comma-Separated Values, can be opened with spreadsheet programs like Microsoft Excel or Google Sheets and can also be uploaded into programming environments.
Whether you’re a climate enthusiast, a planner, a researcher, or just curious about Canada’s climate – you can explore the climate variables that are most relevant to you.
Download data for Canada on ClimateData.ca:
2. Search by Variable: When exploring climate variables, you can click on any grid cell or area (watershed, census subdivision, or health region) from the Map/Variable view. A timeseries graph will appear for that location, and download buttons are available near the top left corner.
3. Analyze page: Work through the steps along the left side of the webpage to select your data sets, locations, variables, and timeframes. For Step 5, under “Advanced”, you can select your output format, including an option for a “CSV” spreadsheet.
4. Download page: Step 6 in the data selection is to “Select a data format”. A CSV spreadsheet is the default option.
The partner organizations behind ClimateData.ca want users to feel empowered to customize their data and walk away with usable information. Now that you know where to download the data and what kind of files you can produce, let’s take a closer look at what is included in a CSV spreadsheet from our portal.
Using the guide below, learn how to “speak the language” of a climate data download file, with links along the way to learn more.
The first thing you may notice when you open one of the CSV files in Microsoft Excel is that the “time” column is showing “########”. To see the full dates and times, widen the column a bit until you see the dates appear.
Here’s how to decipher the date:
For more information on why it’s beneficial to consider 30 years of data when making decisions concerning future climate change, check out the Climate Science 101: Importance of Using 30 Years of Data article.
Next, you may see some “lat” and “lon” columns. These represent the latitudes and longitudes of the grid cell(s) that you have selected.
To help remember the location for which you downloaded the data, or if you’re downloading data for multiple areas at once, re-label the files to add in location information such as:
The rest of the columns follow a predictable format. The generic version of the column header follows a standard naming convention and will look something like this:
In a real-world example of data downloaded from ClimateData.ca, your column headers may look something like these:
The portion starting with “delta” are change values, known as delta values. This section only shows up in the column headers if you’ve chosen to download a file that includes the “30 year change” values that you see on ClimateData.ca.
If you’d like more information on baseline periods, check out this Ask a Climate Expert: Navigating the Intricacies of Baseline Periods blog post.
This part of the naming convention tells you which emissions scenario the data is for. It is typically organized in ascending order as shown below:
More information on emissions scenarios is available in the ClimateData.ca Learning Zone in the following articles: Emissions Scenarios: RCPs and Understanding Shared Socio-economic Pathways (SSPs)
The last part of the column header naming convention used on ClimateData.ca refers to the percentiles of the data being shown.
The default options for percentiles shown on ClimateData.ca are the 10th, 50th and 90th percentiles. In the file names, we use the following naming conventions:
For more information on what percentiles are, check out this Learning Zone article on Understanding Multi-Model Ensembles that gives a visual example of how percentiles are calculated.
You don’t have to be an expert in climate science to start using climate data. Get more acquainted with climate data today and let us know where we can help. Remember, we’re here to support you along the journey.
Stay tuned for more posts in our “Ask a Climate Expert” series, where we’ll continue to break down complex climate concepts. Until then, keep the questions coming and happy data downloading!