A view of Earth from the GOES-16 satellite on Nov. 8, 2017. (NOAA)

The climate is changing faster than it has in thousands of years and will have enormous consequences on the environment and how we live, a blockbuster U.S. government report said last week.

But what if we lose the ability to monitor these changes? How we will know how fast they are happening? Without such key measurements, how will our predictions — which rely on them-  be able to inform us about the future and what people and places are most at risk? And, then, what will be the economic costs of being caught ill-prepared?

Climate scientists are deeply concerned about what they see as an endangered network of global observations vital for understanding present and future climate changes.

In a paper released Thursday, 26 scientists, including four laboratory directors at the National Oceanic and Atmospheric Administration, unveiled a blueprint for the observing network of the future. It calls for a coordinated and expanded observing network that is focused on answering key scientific questions that respond to the needs of society and that leverages emerging technology.

The need for the implementation of such a plan is pressing, they say. Elizabeth Weatherhead, the lead author of the paper and an atmospheric scientist at the University of Colorado, said a lot climate observing systems around the world “are just aging out” or their funding is being cut.

“We just closed the two observing stations that are covering the tropics,” she said in an interview. “We have no great understanding of what’s going on with water vapor and temperature in the tropics and we need that within a couple tenths of degree.”

Changes in the tropical atmosphere are seen as crucial for assessing how quickly the Earth is warming due to human activity.

Weatherhead said that even if legacy systems are eventually replaced, gaps develop “which throw us for a loop if we’re looking for long-term trends.” She added that, outside China and to a lesser extent India — which are investing in improved monitoring networks — “we don’t see anything good on the horizon.”

“The current decline of our Earth observing systems is likely to continue into the foreseeable future,” said Liz Moyer, a climate researcher at the University of Chicago, in a news release. She was not involved in the paper. “Unless action is taken—such as suggested in this paper—our ability to plan for and respond to some of the most important aspects of climate, including extreme events and water availability, will be significantly limited.”

Weatherhead emphasized that monitoring the climate demands specialized observations, which other types of measurements do not necessarily satisfy.

“We have lots of observations designed for other things: weather, basic earth research, crops, water resources, etc.,” she said.  “But very few of them are designed with sampling and accuracy required to resolve the one percent or smaller changes over decades that are critical to testing climate prediction.”

The task of comprehensively monitoring the climate is far from trivial. Bruce Wielicki, a climate scientist at NASA and second author on the paper, said you need to measure “about 50 different variables at high accuracy versus about 6 for weather.” It involves sampling the deep oceans, the chemistry of the atmosphere, ecosystem changes, ice sheets, among other things, he said. And this often requires deploying instruments in remote locations, Weatherhead noted, which is expensive.

From study: “Designing the Climate Observing System of the Future.” (AGU)

But the economic benefits of a robust global climate observing network are massive, the paper argues.

One of the most thorny challenges facing climate scientists is narrowing down how much the planet will warm from a doubling of the amount of carbon dioxide in the atmosphere — or the so-called climate sensitivity.

“Narrowing uncertainty in critical climate science such as climate sensitivity has an estimated value of $10 to 20 trillion U.S. dollars to the world and $1.5 to $3 trillion to the U.S,” Weatherhead said, referring to scientific studies cited in her paper. “Much more accurate and complete observations are critically needed to narrow these types of uncertainties in our future.”

In addition to improving understanding of climate change, better data from improved monitoring would aid seasonal climate prediction, which would also have economic benefits, Weatherhead said.

Weatherhead said that for the next generation observing system to be successful, it will need to be built to respond to the key questions posed by scientists and use the best tools for the job. “What gives us hope is the incredible development in observing systems in last two decades: unmanned aircraft, autonomous underwater vehicles, individual cellphones as pressure sensors, citizen science, and more,” she said. “What we’re hoping to do is by making clear what the key science questions are, all kinds of innovation can flourish.”

The paper, Designing the Climate Observing System of the Futureis published in Earth’s Future, an online journal of the American Geophysical Union.