Delving Deeper into Radiative Forcing and the Role of Business Travel

Radiative Forcing series, part 2: understanding the hidden impact of business travel, specifically air travel, on global warming

Written by Cameron Kelly on 30 August, 2023


In our previous article, we introduced the concept of radiative forcing and its critical role in driving climate change. In this article we'll uncover the hidden impact of business travel, specifically air travel, on radiative forcing and, consequently, on global warming.

1. You can actually see Radiative Forcing at work in the sky

Have you ever seen the white cloud-looking streaks off the back of airplanes? Those are called “aircraft contrails”. They are line-shaped clouds that form when hot humid air from an aircraft engine mixes with low-pressure, low-temperature air in the atmosphere, which contribute significantly to radiative forcing. Contrails can trap solar radiation within the Earth's atmosphere, leading to warming. Despite their transient nature, contrails can have a long-term climate impact that rivals the warming effect of aircraft CO2 emissions (i.e. yes, they are a big deal).

2. Not all contrails are the same: The Impact of Flight Timing, and Altitude, and Engine Types

Interestingly, not all contrails have the same climate impact. Contrails produced during dawn and dusk, and when aircraft are cruising at altitudes between 35,000 and 41,000 feet, have the most significant warming effect. Mid-day contrails can sometimes have a net cooling effect as they reflect sunlight back into space.

These variations in contrail effects highlight how different aspects of flight operations, such as scheduling and route selection, can influence the overall climate impact of business travel.

The 'cleanness' of engine burn can also influence contrail formation. Engines that produce fewer soot particles generally cause fewer contrails. As we move towards cleaner fuels, such as Sustainable Aviation Fuel (SAF) and potentially hydrogen, the picture may become more complex, requiring further research. In a nutshell, not all contrails (and their effects on Radiative Forcing) are made the same.

3. Tools for unraveling the complexity and getting to and getting to Change: Carbon Calculators and Ssustainable Decision-Making

In this era of heightened environmental awareness, having accurate, actionable information is key to making sustainable decisions. For Travel Managers tasked with navigating the complexities of business travel, cutting-edge tools and resources that provide detailed insight into the carbon footprint of travel activities are becoming increasingly important.

Carbon Calculators

One such powerful tool at the disposal of Travel Managers is the carbon calculator. At Thrust Carbon, we have developed a sophisticated carbon calculator designed to deliver a comprehensive picture of your company's carbon emissions associated with travel.

Our calculator does not merely account for the carbon dioxide emissions resulting from the combustion of jet fuel. It goes a step further by taking into consideration non-CO2 impacts, including those from contrails and other high-altitude effects. This ensures you get an accurate, holistic view of your business travel's environmental impact, which is crucial for developing and implementing effective sustainability strategies.

Flight Optimization

Another area where organizations can tackle this issue is in flight optimization. By analyzing a variety of factors including flight timing, aircraft model, engine type, altitude, and routing, Thrust Carbon’s Advisory team can provide the analysis and policy suggestions for lower-emission alternative routes. For instance, flights scheduled for the night may result in fewer contrail formations, reducing their overall climate impact. Similarly, choosing airlines that operate newer, cleaner-burning engines can significantly cut down on emissions.

Reporting and Compliance

Another crucial aspect of Thrust Carbon’s toolset is comprehensive emissions reporting. This can be pivotal when it comes to meeting regulatory requirements, complying with industry standards, or working towards voluntary emissions targets. Our system generates detailed reports that not only track your business' carbon footprint but also offer valuable insights to help you identify key areas where emission reductions are achievable.

Education and Training

Moreover, we believe that tools for change extend beyond software. To that end, Thrust Carbon is building more educational resources and training to help Travel Managers better understand the environmental impacts of various aspects of air travel. Our aim is to empower you with knowledge, allowing you to lead meaningful discussions and drive impactful travel policies for sustainable business travel within your organization.


Radiative forcing, a complex phenomenon, plays a significant role in the contribution of business travel to climate change. As we pursue greener travel practices, it becomes imperative to grasp the hidden aspects of travel's climate impact. By harnessing intelligent tools and making well-informed choices, Travel Managers can become trailblazers in promoting sustainable business travel. Through such efforts, we not only reduce our carbon footprint but also align with broader corporate sustainability strategies, fostering a healthier planet for generations to come.

This blog is one of a 3-part series on radiative forcing. Read part 1 here and part 3 here.

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