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Ask Zachary Foltz

Questions of the Climate Detectives Webinar: Major natural & man-made disasters from space

Students could send ESA their Earth related questions until 5 December 2024. These questions were partly answered by the expert in the webinar. To answer all submitted questions by the teams, Zachary Foltz wrote the answers down to help teams investigating their projects and give more insight in relevant topics.

Thanks a lot!

About Zachary Foltz

My name is Zach Foltz, I am currently a research engineer at ACRI-ST, a remote sensing company in the South of France. My work primarily consists of supporting ESA on activities related to the International Charter ‘Space and Major disasters’ and the ‘Committee on Earth Observations Satellites’ Working Group on Disasters, which are both humanitarian initiatives involving the use of Earth Observation data to better manage disaster situations worldwide. The International Charter focuses on the immediate response phase of natural and man-made disaster events, such as floods, wildfires, Earthquakes, oil spills, etc. During disasters, satellites from the 17 member agencies of the Charter provide rapid imagery of the affected areas, even in remote or inaccessible regions. This information can aid experts in assessing damages, organizing relief operations, and planning the best way to rebuild. I studied Civil Engineering with a focus in water resources and urban planning and did my masters in Environmental Hazards and Risks Management at the University of Nice in France. My transition from Civil engineering to the Earth Observation and disaster management sphere stems from combining my technical background with a passion for the critical environmental challenges we face as a society today.

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Your questions
Disasters

Yes, astronauts regularly observe and photograph disasters (e.g., hurricanes, wildfires) and environmental changes like deforestation or shrinking glaciers, providing a unique perspective on Earth’s transformations.

Differentiating between man-made and natural disasters can be challenging, especially since many disasters are now influenced by human activity. Disasters are generally classified into two broad categories:

  • Natural Disasters: These originate from natural processes of the Earth, such as earthquakes, hurricanes, tsunamis, volcanic eruptions, or wildfires.
  • Anthropogenic (Man-Made) Disasters: These are caused directly or indirectly by human actions, such as industrial accidents, oil spills, nuclear disasters, or deforestation-induced floods.

However, the distinction is increasingly blurred:

  • Climate-Amplified Natural Disasters: For example, wildfires are natural phenomena, but their frequency and intensity are amplified by human-induced global warming and poor land management.
  • Hybrid Disasters: Events like dam failures during floods or landslides triggered by deforestation involve both natural and human components.

A more nuanced classification approach considers the underlying causes and contributing factors:

  • Primary Cause: Was the event initiated by a natural process or human action?
  • Contributing Factors: Did human activities amplify the severity, frequency, or impact?

For instance, a wildfire in a dry season might be classified as “natural” if lightning caused it, but if exacerbated by human-induced climate warming, it would be labeled as “climate-influenced.” Thus, disasters often exist on a spectrum between natural and man-made causes.

Satellites can’t stop natural disasters, but they could improve prevention efforts by providing early warnings. For example, monitoring sea surface temperatures could help predict hurricane formation earlier. However, physically disrupting a storm (e.g., with chemical dispersal) is currently unfeasible due to technological and ethical limitations.

Yes, satellites monitor atmospheric and oceanic conditions (e.g., Sentinel-3 for sea surface temperature and Sentinel-5P for atmospheric composition). Accurate forecasts improve disaster preparedness, protect crops, and reduce economic losses.

Space technology enables real-time disaster monitoring (floods, fires, earthquakes), early-warning systems, and damage assessments for post-disaster recovery. For example:

Sentinel-1: Monitors floods and ground displacement.

Sentinel-2: Tracks vegetation recovery after wildfires.

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Disasters are predicted using remote sensing (e.g., temperature, soil moisture, tectonic activity) and models combining satellite data with meteorological records. For example:

      • Πλημμύρες: Monitored using precipitation and soil moisture data.
      • Droughts: Predicted via vegetation indices and rainfall anomalies.

Stay Informed: Stay updated on local weather patterns, seasonal risks (like floods, storms, or heatwaves), and potential natural disasters. Follow official sources like meteorological agencies and local emergency services

Create an Emergency Plan: Have a family emergency plan that includes safe meeting points, emergency contacts, and evacuation routes. Keep a disaster supply kit with essential items like water, non-perishable food, flashlights, batteries, first aid supplies, and important documents in a safe, easily accessible place.

Strengthen Your Home: Depending on the risks in your area, reinforce your home to make it more resilient. For example, securing windows and doors for hurricanes or ensuring your house is fire-resistant in wildfire-prone areas

In the future, Earth observation technology will become much better at helping us predict and respond to natural disasters. New satellites will take clearer and more frequent pictures of the Earth, allowing us to track storms, floods, and wildfires in real-time. Advanced sensors will measure changes in the land, oceans, and atmosphere, helping scientists predict events like earthquakes or hurricanes earlier. Drones and AI will work alongside satellites to analyze data faster and guide rescue efforts. These tools will make it easier to prepare for disasters, save lives, and protect communities.

Earthquakes are the most challenging since they occur suddenly and are difficult to predict. Satellites can only monitor post-disaster effects, such as ground displacement or infrastructure damage.Unlike hurricanes or floods, which can be tracked as they develop, earthquakes occur deep underground, making it very hard to detect them before they strike. Satellites can’t “see” inside the Earth to know when the tectonic plates are going to shift. What satellites can do is help after the earthquake has already happened. They can use special tools, like Synthetic Aperture Radar (SAR), to map how the ground moved during the quake. This helps scientists see where the damage is worst and guide rescue teams to the areas that need the most help. Satellites can also provide real-time images of roads, buildings, and bridges that might have collapsed, helping people plan recovery efforts. While researchers are working on ways to better predict earthquakes, we currently rely on ground-based sensors like seismometers to detect them. Satellites are more useful for assessing the impact after the quake rather than preventing it.

Sentinel-1: Tracks floods and landslides using radar.

Sentinel-2: Monitors wildfires and vegetation health.

Sentinel-3: Observes sea surface temperatures for storm predictions.

Sentinel-5P: Analyzes air pollution and volcanic eruptions.

When multiple disasters occur at the same time, ethical dilemmas arise around how to prioritize satellite resources. For example, should satellite data be allocated to the most severe disaster, or should it be spread equally across all affected areas, even if some might have a lower immediate impact? Deciding which regions or events get the most attention can raise difficult questions about fairness, equity, and the balance of resources. Additionally, some regions might lack the technological capacity to effectively use the satellite data, leading to concerns about ensuring equal access to critical information for disaster response. Solutions involve international collaborations (e.g., CEOS) to coordinate satellite use equitably.

Yes, it is possible to detect and analyze the intensity of a storm in real time using satellite data. Storm intensity can be monitored through a combination of weather satellites and advanced sensors, which track various parameters like wind speed, cloud structure, and rainfall. Satellites like Meteosat (EUMETSAT) και GOES (NOAA) continuously monitor weather conditions over Europe and other regions in real time. They provide high-frequency images (every 5–15 minutes) that show storm formation, cloud movement, and intensity.

Satellites can:

      • Detect harmful agricultural runoff causing algal blooms in oceans.
      • Monitor industrial emissions, providing data for regulations.
      • Track microplastics in water and atmospheric particulate matter.
      • Aid in precision agriculture by optimizing water and fertilizer use.

The main obstacles to international collaboration in disaster response using Earth observation satellites include:

  1. Political and Legal Barriers: Countries may have different policies about sharing satellite data, particularly if the data is sensitive or related to national security. This can delay or limit access to crucial information in disaster situations.
  2. Technological Gaps: Not all countries have the same level of access to the latest satellite technology or the ability to process and interpret data quickly. This can create imbalances in how quickly some countries can respond to disasters.
  3. Data Sharing and Coordination:  There can be challenges in coordinating sharing satellite data, due to differences in satellite systems, data formats, or communication networks.

To overcome these obstacles, organizations like the Committee on Earth Observation Satellites (CEOS) work to ensure data is freely shared and accessible in times of crisis. By standardizing data formats, improving international agreements, and setting up rapid data-sharing protocols, these challenges can be minimized, leading to more coordinated and effective disaster responses.

Κλιματική αλλαγή

Europe has been experiencing an increase in extreme weather phenomena due to the warming climate. This trend is driven by several factors:

Climate Change: Global warming is amplifying extreme events like heatwaves, floods, and storms. Warmer temperatures lead to greater evaporation, more moisture in the atmosphere, and intensified rainfall events.

Jet Stream Disruption: The warming Arctic is weakening and destabilizing the jet stream, which can cause prolonged weather patterns in Europe, such as extended heatwaves or intense storms.

Mediterranean Tropical-Like Cyclones (Medicanes): Warmer sea surface temperatures in the Mediterranean can create hurricane-like storms similar to those seen in the Gulf of Mexico, although on a smaller scale.

Urbanization and Land Use Changes: Increased urbanization and deforestation can exacerbate the impacts of such phenomena, such as worsening flash floods and urban heat islands.

Higher temperatures slow down the Gulf Stream by disrupting the thermohaline circulation, which relies on temperature and salinity gradients. This slowdown can lead to stronger storms, sea level rise on US coasts, and colder winters in Europe.

Weather modification technologies (e.g., cloud seeding) exist but are limited to small-scale effects, such as increasing rain locally. Large-scale manipulation, like creating storms, is beyond current capabilities.

Yes, people have developed some ways to influence weather, but the effects are limited. For example, “cloud seeding” involves adding tiny particles (like silver iodide) to clouds to encourage rain. This method has been used in some places to increase rainfall, especially during droughts. However, it’s not 100% reliable, and it’s impossible to fully control where or how much it rains. Creating or controlling major weather events like hurricanes is not possible with current technology.

ESA contributes by developing and deploying satellites (e.g., Sentinel series under Copernicus) that monitor greenhouse gas emissions, deforestation, and ice loss. It also funds innovative projects like carbon capture analysis, renewable energy monitoring, and early-warning systems for extreme weather.

ESA satellites measure air pollution (e.g., NO₂, CO₂, methane), monitor ocean health (e.g., plastic pollution, temperature), and track deforestation or desertification. This data helps policymakers create sustainable strategies, such as reforestation projects or urban air-quality initiatives.

ESA’s research and technology focus on leveraging cutting-edge satellite systems to address the twin challenges of pollution and climate change. Satellites like Sentinel-5P και Copernicus Anthropogenic CO₂ Monitoring Mission (CO₂M) measure CO₂ and methane emissions globally. These tools help verify compliance with international agreements like the Paris Climate Accord. ESA’s GlobEmission project combines satellite data with modeling to identify and track industrial emissions in real time. ESA promotes urban air quality monitoring using satellite data and integrates it with ground sensors to develop cleaner city designs. CryoSat-2 measures ice thickness, while Sentinel-1 tracks glacier movements. This data is critical for understanding sea-level rise. Sentinel-3 measures sea surface temperature and ocean color to monitor marine ecosystems affected by climate change.

Satellites and innovative remote sensing techniques are becoming indispensable for monitoring and managing environmental pollution caused by human activities. On the terrestrial side, Satellites like Sentinel-2 can monitor crop health, detect over-fertilized areas, and map nutrient runoff using spectral bands sensitive to vegetation and soil moisture. This data can guide precision agriculture practices to reduce environmental impacts. High-resolution satellites such as WorldView-3 and Sentinel-2 can track illegal waste dumping and monitor industrial emissions. On the marine side, SAR (e.g., Sentinel-1) can detect oil spills on the ocean surface even in poor weather or at night, enabling faster response and cleanup efforts. Algal blooms caused by excess nutrients (from fertilizers) can be tracked using chlorophyll-a concentrations measured by Sentinel-3’s Ocean and Land Colour Instrument (OLCI). In general, Continuous monitoring supports evidence-based policymaking, such as setting limits on agricultural runoff, emissions, and deforestation.

Advocate for change via social media, participate in local sustainability projects, and promote awareness through education and activism. Young people can lead by example through sustainable lifestyles and by pressuring policymakers to act.

Yes, it is likely that the demand for remote sensing experts will increase due to climate change. Remote sensing technologies, such as satellites, drones, and aerial imaging systems, play a critical role in:

  • Monitoring Environmental Changes: Detecting changes in glaciers, sea levels, deforestation, desertification, and urban expansion.
  • Disaster Prediction and Response: Identifying early warning signs for hurricanes, floods, wildfires, and droughts. For example, remote sensing can track fire-prone areas by monitoring vegetation dryness and temperature.
  • Carbon Emissions Monitoring: Mapping and quantifying carbon sources and sinks, aiding in international climate agreements and policies.
  • Post-Disaster Assessment: Evaluating the extent of damage and supporting recovery efforts after disasters.

As the impacts of climate change grow, governments, researchers, and private sectors will increasingly rely on remote sensing data for mitigation and adaptation strategies. Climate change is driving an urgent need for accurate, real-time data about the Earth’s systems to inform decision-making, develop mitigation strategies, and predict future scenarios. Remote sensing has become a cornerstone of addressing climate-related challenges.

Questions about teams projects

Sentinel-2 is ideal for this. Its multispectral imaging includes NIR and VIS bands, making it suitable for vegetation analysis and comparison with drone imagery. Sentinel-2 satellites revisit any location on Earth every 5 days, allowing near-real-time monitoring of vegetation changes. Sentinel-2 data can be used to calculate vegetation indices like NDVI (Normalized Difference Vegetation Index) και NDWI (Normalized Difference Water Index) to detect drought stress, crop health, and biomass anomalies.

Yes, SAR (Synthetic Aperture Radar) technology from Sentinel-1 can detect subsurface features like pipelines or water channels, especially if combined with historical urban expansion maps. While its primary application is surface monitoring, SAR’s ability to detect structural changes and water content below the surface makes it a useful tool in combination with other datasets. While its penetration depth is limited (a few centimeters to meters depending on soil type), it can still detect surface deformations caused by underground water movement, erosion, or subsurface voids.

Mud dust, especially after floods, can contribute to air pollution when dried and dispersed into the atmosphere. Detecting and analyzing this pollution can be achieved using satellite sensors that monitor aerosol particles in the atmosphere. Sentinel-5P (TROPOMI) is ideal for detecting atmospheric pollutants, including dust particles, fine aerosols, and particulate matter (PM). It measures Aerosol Optical Depth (AOD), which indicates the concentration of particles in the air. Sentinel-3 Tracks surface reflectance and aerosol concentrations. It can identify dust dispersion over affected areas.

Plants need water to grow, and precipitation (like rain) is one of the main ways they get it. Too little rain can cause plants to dry out and stop growing, while too much can flood the soil and damage their roots. Soil moisture sensors are tools that measure how much water is in the soil. Farmers and scientists use these sensors to make sure plants get the right amount of water, helping them grow healthy and strong while also conserving water.

Microplastics are tiny pieces of plastic that can float in the air and settle on the land and ocean. These particles can absorb heat from the sun, which might contribute to warming the atmosphere. They can also affect cloud formation by serving as tiny “seeds” for water droplets, potentially changing weather patterns. While scientists are still studying the full effects, microplastics add to the problems caused by pollution and climate change.

Mud dust, especially after floods, can contribute to air pollution when dried and dispersed into the atmosphere. Detecting and analyzing this pollution can be achieved using satellite sensors that monitor aerosol particles in the atmosphere. Sentinel-5P (TROPOMI) is ideal for detecting atmospheric pollutants, including dust particles, fine aerosols, and particulate matter (PM). It measures Aerosol Optical Depth (AOD), which indicates the concentration of particles in the air. Sentinel-3 Tracks surface reflectance and aerosol concentrations. It can identify dust dispersion over affected areas.

How to work with satellite data
  1. Identify the Event Details
  • From the news article, determine the following:
    • Event location (e.g., city, region, or coordinates).
    • Date of the event (or range of dates surrounding the disaster, e.g., floods, wildfires).
  • Παράδειγμα: A flood occurred in Valencia, Spain on October 31, 2024.
  1. Access the Copernicus/Sentinel Platform
  • Navigate to a tool that provides access to Sentinel data:
    • Copernicus EO browser
    • Sentinel Hub EO Browser
  1. Set the Area of Interest (AOI)
  • Use the platform’s map interface to select the affected area.
    • For example, in Copernicus EO Browser:
      1. Search for a location: Pan to the area on the map you would like to visualize data over
      2. Draw an AOI: Define a box or polygon around the affected region.
  1. Specify the Time Range
  • Set the date range or go to a date before the event to include the day of the disaster and days before/after to compare pre- and post-event images.
  • Example: For a flood on October 31, 2024:
    • Start Date: October 10, 2024.
    • End Date: November 10, 2024.
    • Alternatively, visualize a date before the events and scroll through the images across and after the event.
  1. Select the Satellite and Data Type
  • Choose relevant Sentinel data products based on the disaster type:
    • Sentinel-1 (SAR): Excellent for flood detection and monitoring water extent because it can penetrate clouds.
    • Sentinel-2 (Optical): Useful for assessing land damage, vegetation, and infrastructure, but is affected by clouds.
  • Example: If the disaster involved heavy rain and clouds, prioritize Sentinel-1.
  1. Visualize the Imagery
  • Open the satellite images to observe the disaster-affected area.
    • Use pre-configured layers (e.g., “False Color” for vegetation or “Flood Detection” for water).
    • Compare before and after images using the “Compare” or “Swipe” tools.
  1. Download Data (Optional)
  • If deeper analysis is needed, download the data for use in software like QGIS or ArcGIS.
  • Formats are usually GeoTIFF, JPEG, or raw Sentinel data products.
  1. Analyze and Interpret
  • Look for visible signs of the disaster:
    • Πλημμύρες: Water-covered areas (dark on SAR or bright in False Color Composite).
    • Fires: Burn scars or smoke plumes.
    • Landslides: Changes in terrain or vegetation cover.