Climate change is the biggest threat ever experienced by mankind. It refers to the long-term
alteration of temperatures and weather patterns and its effects have become more visible as the
average temperature of the planet went up by 1.2 °C since the 1800s [1]. As Earth warms,
it disrupts natural weather systems, contributing to more frequent and extreme weather events.
The increasing danger of these events is a serious threat to the safety of many populations.
Although addressing climate change requires significant economic and political shifts, we can
also focus on better understanding the changes already occurring. The goal of our project is to
identify trends and visualize extreme weather events that have taken place, while also assessing
their human and economic impact.
To address our research question, we need relevant data. In this project we will focus on events
that have happened in the United States. This is because the United States experiences a high number
of extreme weather events due to its size and diverse geographical and climatic conditions. But also
because of the availability of high-quality data on extreme weather events.Indeed, thanks to
the National Oceanic and Atmospheric Administration (NOAA), we have access to the Storm Events
Database [2], which provides information on the occurrence of storms and other significant weather
phenomena having sufficient intensity to cause loss of life, injuries, significant property damage,
and/or disruption to commerce; Rare, unusual, weather phenomena that generate media attention,
such as snow flurries in South Florida or the San Diego coastal area; Other significant
meteorological events, such as record maximum or minimum temperatures or precipitation that
occur in connection with another event. This database spans from January 1950 to November 2024,
making it particularly valuable for analyzing the impact of climate change on the frequency of
extreme weather events.
We will focus on trying to answer questions such as "How does climate change contribute to
the increasing frequency of extreme weather events in the USA ?" or "What are the
economic and human consequences of the growing occurrence of extreme weather events ?".
Continue to scroll to start by exploring the current situation of climate change in the United
States !
Climate Change in the United States
Temperature Anomalies
To understand how climate change is affecting the extreme weather events we first
need to understand what the current climate situation is in the United States. For that
we start by showing a historical histogram of the average temperature anomalies for the
whole country compared to the 1961-1990 mean average as this is considered, in the scientific
literature, as a good baseline for assessing long term changes [3]. It is obvious
from this histogram that the situation is deteriorating and that all recent years are above the
average.
A legitimate question that can come to mind when looking at the first histogram is
whether or not the situation is the same over the whole country or if some regions, some states
are more spared by the effect of climate change. To answer that question we plot the temperature
anomalies averaged over 2024 but for the different states. It is clear that climate change problem is affecting some
states more intensly. However, none is spared and everyone should be concerned by the problem.
Analysis of Historical Weather Events
We continue our exploration by looking at the historical data of extreme weather events. This is
essential to understand the situation in the United States. We start by presenting some plots with general
statistics that aim to give you a broad overview of which type of events can happen in the United States,
at which frequency, and with which impact. However, as our dataset is quite extensive, covering many years,
many type of events with details concerning economic loss and number of deaths, we are forced to be selective
on what we show. However, to give you the possibility to explore more the data by yourself, you have the
possibility, to filter the data by state, range of years, type of events and then choose which information
you want to plot and on which type of plot.
Total number of events over the years
A first insight on our data is to look at the number of events through the years.
It is very clear that there is more and more events as time passes. However, this
is due, at least in some way, to the fact that the Storm Events Database has been recensing
more types of events. In particular, there are three phases in the recording of data.
The first one, going from 1950 until 1955, only tornadoes were counted and we, thus, obtain very few events.
In 1956, it was decided to also incorporate thunderstorms, strong winds and hail.
Since 1966, 48 different event types are recorded to allow more interpretability and precision.
As expected, the more types of event accounted, the more records there will be,
but, even within the phases, we can see that the number of event increases.
Proportional distribution of event types over time
This map displays the proportional distribution of storm event types across all U.S. states.
For each year, it shows the percentage contribution of each storm type to the total number of recorded events.
Initially, from 1950 to 1955, only tornado events were recorded.
Then from 1955 to 1996, thunderstorms, wind and hail were also recorded.
Finally, from 1997 onwards, 48 types of extreme weather events were being recorded during the year.
These changes in reporting practices explain the increasing diversity of storm types seen in later years.
Deadliest types of events
This histogram highlights the deadliest types of events.
It shows the total number of people that died because of specific types of incidents since the beginning of measurements.
From it, we can see that tornadoes are the deadliest form of events but this may be caused by the recording of only this kind of event as explained before.
Most costly types of events
This histogram highlights the most costly types of events.
It shows the economic cost (in billions of $) of specific types of incidents since the beginning of measurements.
From it, we can see that tornadoes are, by far, the most economically challenging form of events but this may be caused by the recording of only this kind of event as explained before.
Configure your filters and click "Update Plot" to display weather data visualization (this may take a few seconds).
Select States
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Weather Events
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Metric
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Year Range
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Plot Type
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Impact of Climate Change on Events Frequency
As you have maybe found out already above by exploring the data with different kind of plots,
the number of extreme weather events is increasing each year. This rise leads to more crop damage,
deaths and destruction. These events have a very serious a huge impact on society. To better anticipate future extreme
events and mitigate their impact, a better understanding of the factors facilitating the apparition of
weather events is essential. This is also necessary to assess what the consequences of climate
change are on the extreme weather frequency. In this part of our exploration we detail other knwon factors
influencing the number and the scale of weather events in the United States before actually answering scientifically to whether or not climate change has also an impact and in at what scale.
Topographic Map Placeholder
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The topography of the United States
One of the most influential factors, if not the most, is the topography of the country. As you can see
on the map displayed here [3], the elevation and terrain features vary a lot depending on
the regions. Key features include mountain peaks, valleys and ridges. How do
these variations impact the number and type of events ?
Many factors contribute to the local climate of a given area, including proximity to the
equator, the ocean, and elevation. But when it comes to what causes
climate and storm events to vary over seemingly short distances, few things can compare to the influence of
topography[4]. We can not detail everything here and as this is complex area of study additionally,
every factor influencing extreme weather systems is not fully understood by scientists. However,
this text was to remind you that some of the patterns of extreme weather events you might have found while exploring the website above
can be due to external factors such as topography.
As you have maybe found out already above by exploring the data with different kind of plots,
the number of extreme weather events is increasing each year. This results in more crop damage,
deaths and .... This has a huge impact on society in general. To better anticipate future extreme
events and mitigate their impact, a better understanding of the factors facilitating the apparition of
weather events is essential. This is also necessary to assess what are the consequences of the climate
change on the extreme weather frequency. In this part of our exploration we detail other known factors
influencing the number and the scale of weather events in the United States before actually trying to
answer scientifically to whether or not climate change has also an impact and in at what scale.
"Scientific studies indicate that extreme weather events such as heat waves and large
storms are likely to become more frequent or more intense with human-induced climate
change"
EPA, 2023 [5]
"Warming increases the likelihood of extremely hot days and nights,
favors increased atmospheric moisture that may result in more frequent
heavy rainfall and snowfall, and leads to evaporation that can exacerbate
droughts"
National Academies of Sciences, 2016
[6]
"It is an established fact that human-induced greenhouse gas
emissions have led to an increased frequency and/or intensity
of some weather and climate extremes since pre-industrial
time, in particular for temperature extremes"
IPCC, 2021 [7]
"Advancing scientific capability now makes it possible to make and defend
quantitative statements about the extent to which human-induced climate change
has influenced either the magnitude or the probability of specific types of
event or event classes"
Science, 2016
[8]
Conclusion
Through data and visualizations, we have learned that climate change has a role in
the increasing number of events even though it is not the only factor. However, climate change
has other consequences and since it is increasily costly both economicaly and in terms of casualties,
it is necessary to react quickly to both mitigate its consequences as well
as reduce emissions in order to diminish future disasters.
Meet the team
Luc
Master in Data Science
Timo
Master in Life Sciences Engineering with a minor in Data Science
[6] National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press.
https://doi.org/10.17226/21852
[7] IPCC. (2021). Weather and climate extreme events in a changing climate (Chapter 11). In V. Masson-Delmotte, P. Zhai, A. Pirani, et al. (Eds.), Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 1513–1766). Cambridge University Press.
https://doi.org/10.1017/9781009157896.013
