Spectroscopy: A Key Tool for Climate Change

By Ankit SinghReviewed by Susha Cheriyedath, M.Sc.Jul 29 2024

Spectroscopy, the study of the interaction between matter and electromagnetic radiation, has evolved significantly since its inception. Initially used for astronomy, it now includes many techniques applied across scientific fields. In the context of climate change, spectroscopy provides an effective means for monitoring environmental changes, analyzing greenhouse gases, and evaluating the health of ecosystems.

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Evolution and Principles of Spectroscopy

Spectroscopy began with Isaac Newton's experiments with prisms in the 17th century, revealing the spectrum of visible light. Over the years, it has grown and encompasses many parts of the electromagnetic spectrum, ranging from radio waves to gamma rays. It involves calculating the amount of radiation absorbed, emitted, or scattered by materials and information concerning their composition, structure, and physical characteristics.

Modern spectroscopy techniques include infrared (IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Raman spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. These methods depend on different modes of interaction between radiation and matter. They may be used in a wide spectrum of tasks connected with environment control, chemical analysis, or medical diagnostics. The diverse range of spectroscopic techniques allows scientists to choose the most appropriate method based on the specific properties of the sample and the type of information needed.

Spectroscopy's Crucial Role in Climate Change Mitigation

Spectroscopy provides invaluable tools for addressing climate change, enabling precise monitoring of environmental parameters. From greenhouse gas measurements to assessing ocean health, these techniques offer critical insights necessary for effective climate action.

Monitoring Greenhouse Gas Emissions

One of the most critical applications of spectroscopy in combating climate change is monitoring greenhouse gas emissions. Techniques such as Fourier-transform infrared (FTIR) spectroscopy and tunable diode laser absorption spectroscopy (TDLAS) are used to measure concentrations of carbon dioxide (CO₂), methane (CH₄), and other greenhouse gases with high precision. These methods enable real-time monitoring of emissions from industries, power plants, and even from plants and other natural systems.¹

Spectroscopy using satellites such as the Orbiting Carbon Observatory-2 (OCO-2) offers Global CO₂ measurement, which helps scientists to localize emission sources and sinks accurately. This comprehensive data supports the verification of climate agreements and the development of strategies to reduce greenhouse gas emissions, ultimately aiding in effective climate change mitigation.¹

Assessing Air Quality and Pollutants

Air quality monitoring is essential for understanding and mitigating the impact of climate change on human health. Spectroscopic techniques, including differential optical absorption spectroscopy (DOAS) and laser-induced fluorescence (LIF), are employed to detect pollutants such as nitrogen oxides (NO_x), sulfur dioxide (SO₂), and volatile organic compounds (VOCs). These methods offer real-time, high-resolution data on air pollutant levels, contributing to the development of effective air quality management strategies.¹

These methods assist in identifying the sources of pollution as well as assessing emission reduction measures. Recent advancements in portable spectroscopic instruments enable air quality monitoring in diverse environments, contributing valuable data for public health studies and environmental regulations, and ultimately aiding in the formulation of policies to protect public health.¹

Studying Ocean Health and Carbon Sequestration

The oceans play a vital role in regulating the Earth's climate by absorbing a significant portion of atmospheric CO₂. Spectroscopy aids in studying ocean health and the processes involved in carbon sequestration. For example, Raman and absorption spectroscopy are used to analyze the composition of marine phytoplankton and the efficiency of biological carbon pumps. These techniques help scientists understand how oceanic processes contribute to the global carbon cycle and how they are affected by climate change.²

Research demonstrates spectroscopy's role in monitoring ocean acidification and its impact on marine ecosystems. By analyzing seawater and marine organisms, spectroscopy provides valuable information about the effects of increased CO₂ levels on ocean chemistry and biodiversity, supporting strategies to protect aquatic ecosystems and enhance carbon sequestration.²

Analyzing Ice Cores and Paleoclimate Records

Ice cores provide valuable records of past climate conditions, offering insights into natural climate variability and the effects of human activities. IR and Raman spectroscopy are employed to analyze the chemical composition of ice cores, including trapped gases and impurities. These analyses help reconstruct historical atmospheric conditions and improve climate models, enhancing the understanding of long-term climate change trends.³

Analysis of ice core samples enables scientists to detect fluctuations in greenhouse gas levels, temperature, and atmospheric constituents over millennia. This information is crucial for understanding the natural variability of the Earth's climate and the impact of human activities on the climate system. Spectroscopy provides detailed data on the past environment, helping to validate and improve predictive climate models.³

Detecting and Mapping Methane Leaks

Methane is a potent greenhouse gas. Methane leaks from natural gas infrastructure pose significant environmental risks. Advanced spectroscopic techniques, including laser absorption spectroscopy and cavity ring-down spectroscopy (CRDS), are employed to quickly identify and quantify methane leaks with exceptional precision. By rapidly identifying leak sources and quantifying methane emissions, these methods enable efforts to reduce greenhouse gas releases.⁴

Advancements in drone-based spectroscopy allow for large-scale methane leak monitoring, including in remote locations. This technology supports efficient detection and mitigation of methane emissions from infrastructure, contributing to efforts to reduce the energy sector's greenhouse gas footprint and mitigate climate change impacts.⁴

Evaluating Soil Health and Carbon Storage

Soil health and its capacity to store carbon are critical for mitigating climate change. Near-infrared (NIR) and mid-infrared (MIR) spectroscopy are employed to assess soil organic matter, moisture content, and nutrient levels. These techniques provide rapid, non-destructive analyses that support sustainable agricultural practices and soil carbon management strategies.⁵

Spectroscopy helps farmers implement practices enhancing soil carbon storage and fertility. Research demonstrates spectroscopy's ability to monitor changes in soil carbon over time, offering valuable data for carbon sequestration projects and climate mitigation initiatives. This promotes sustainable land management and reduces greenhouse gas emissions.⁵

Challenges and Considerations

Despite its numerous advantages, spectroscopy faces several challenges in its application to climate change research. Achieving high sensitivity and accuracy in measurements, particularly in remote sensing, can be difficult due to atmospheric interferences and instrument limitations. Ensuring consistent and reliable data across various environmental conditions requires ongoing advancements in instrument design and calibration techniques.

Data processing and interpretation present another significant challenge. The substantial volumes of data generated by spectroscopic techniques pose a significant analytical challenge, necessitating advanced algorithms and substantial computational resources for effective processing and interpretation. Developing efficient workflows and incorporating machine learning can enhance the accuracy and usability of this data.

Cost and accessibility are major concerns, as high-resolution instruments and satellite missions are expensive, limiting availability. Reducing the cost of these tools and expanding access to satellite data is crucial to ensure all regions can benefit from these technologies in their climate change mitigation efforts.

Calibration and standardization are critical for reliable and comparable results. Establishing international standards and guidelines for spectroscopic measurements can improve data quality and facilitate collaboration among researchers and policymakers, enhancing the global response to climate change.

Recent Breakthroughs

The field of spectroscopy is continually evolving, with new research and developments driving innovation and improving the effectiveness of spectroscopic techniques in addressing climate change.

A recent JQSRT study demonstrated a novel application of quantum cascade laser (QCL) spectroscopy for real-time monitoring of atmospheric N₂O and methane levels. The researchers developed a portable, high-sensitivity QCL spectrometer capable of detecting trace gas concentrations with unprecedented precision. This advancement allows for more accurate and timely measurements of greenhouse gas emissions, supporting efforts to track and mitigate climate change impacts.⁶

A recent study published in Soil and Tillage Research demonstrated the combination of visible-to-near-infrared (VNIR) and MIR spectroscopy to analyze soil organic carbon (SOC) levels. The researchers developed a new VNIR-MIR spectroscopic method that provides rapid, non-destructive measurements of SOC content in soil samples. This technique offered advantages over traditional methods, including faster analysis and lower sample requirements. The study suggested the potential of combination spectroscopy to support soil carbon management and address climate change.⁷

Future Prospects and Conclusions

The future of spectroscopy in tackling climate change appears promising, with ongoing advancements in instrumentation, data processing, and integration with other technologies. Emerging techniques such as quantum cascade laser spectroscopy and VNIR-MIR spectroscopy offer new possibilities for high-resolution, real-time environmental monitoring. Additionally, the integration of artificial intelligence (AI) and machine learning (ML) with spectroscopic data analysis holds great potential for improving predictive models and decision-making processes.

In conclusion, spectroscopy is a powerful tool in the fight against climate change, providing critical insights into greenhouse gas emissions, air quality, ocean health, and more. Continued advancements and collaborations across scientific disciplines will enhance the ability to monitor and mitigate the impacts of climate change, contributing to a more sustainable and resilient future.

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References and Further Reading

1. Raychaudhuri, B. (2024). Spectroscopic techniques conceptualized with the remote sensing of atmospheric carbon dioxide and other greenhouse gases. Applied Spectroscopy Reviews, 1–29. DOI: 10.1080/05704928.2024.2326527. https://www.tandfonline.com/doi/abs/10.1080/05704928.2024.2326527
2. Panepinto, D., Riggio, V.A., Zanetti, M. (2021). Analysis of the Emergent Climate Change Mitigation Technologies. International Journal of Environmental Research and Public Health, 18(13), 6767. DOI: 10.3390/ijerph18136767. https://www.mdpi.com/1660-4601/18/13/6767
3. Song, J. (2023). Ice Core Methane Analytical Techniques, Chronology and Concentration History Changes: A Review. Sustainability, 15(12), 9346. DOI: 10.3390/su15129346. https://www.mdpi.com/2071-1050/15/12/9346
4. Strahl, T., et al. (2021). Methane leak detection by tunable laser spectroscopy and mid-infrared imaging. Applied Optics, 60(15), C68. DOI: 10.1364/ao.419942. https://opg.optica.org/ao/fulltext.cfm?uri=ao-60-15-C68&id=450164
5. Barthès, BG., Chotte, J. (2020). Infrared spectroscopy approaches support soil organic carbon estimations to evaluate land degradation. Land Degradation & Development, 32(1), 310–322. DOI: 10.1002/ldr.3718. https://onlinelibrary.wiley.com/doi/abs/10.1002/ldr.3718
6. Shen, F., et al. (2024). Real-time monitoring of CH4 and N2O emissions from livestock using mid-infrared external cavity quantum cascade laser absorption spectroscopy. Journal of Quantitative Spectroscopy and Radiative Transfer, 327, 109131. DOI: 10.1016/j.jqsrt.2024.109131. https://www.sciencedirect.com/science/article/abs/pii/S0022407324002383
7. Hong, Y., et al. (2022). Fusion of visible-to-near-infrared and mid-infrared spectroscopy to estimate soil organic carbon. Soil and Tillage Research, 217, 105284. DOI: 10.1016/j.still.2021.105284. https://www.sciencedirect.com/science/article/abs/pii/S0167198721003573

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