Climate change: it's a subject that is full of uncertainties. That's especially true in the case of how it will affect plant life around the globe. Past studies have revealed that a warming world and changing atmosphere could help plants spread and grow. However, new research has now found evidence of the complete opposite. Plants, it appears, may actually be running out of time to grow in the face of climate change.

That's at least according to a study recently published in the journal PLOS Biology, which details how - as long as trends stay on their current track - climate change will lead to an overall decline in plant growing days by 2100.

And according to research lead Camilo Mora, of the University of Hawai'i, a warming world will be only half the cause. A primary driver of this decline, he and his colleagues found, could be sunlight's own limits.

"Those that think climate change will benefit plants need to see the light, literally and figuratively," Mora said in a statement.

He's talking about experts who have theorized that rising carbon levels in our atmosphere can only be good for plants, encouraging their growth. Others have theorized that warming will free up more soil in once permafrost locked regions. (Scroll to read on...)

"A narrow focus on the factors that influence plant growth has led to major underestimations of the potential impacts of climate change on plants... exposing the world to dire consequences," Mora added.

He and his colleagues specifically point to the northern hemisphere, a region that supposedly could become a plant paradise.

After comparing satellite data on temperature, groundwater levels, and sun exposure, the researchers determined that the north would indeed see a great deal of frozen land get thawed. In fact, the number of days that high-altitude regions will remain unfrozen each year will likely rise by about seven percent. However, they also found that plants trying to live in this newfound world won't stand a chance.

"Regions at higher latitudes will likely have less frost and snow on the ground in the future, but many plants will not be able to take advantage of those warmer temperatures because there will not be enough sunlight to sustain their growth," explained study co-author Iain Caldwell.

The researchers also looked south, towards tropical regions that already are botanical havens. They feared that any warming beyond the norm could adversely impact growth, and they look to be right. Specifically, they found that change-driven drought patterns and overheating could mean that many tropical species wind up with a stunning 200 fewer days to grow before local climes become punishing for plants. (Scroll to read on...)

"Although plants that have already adapted to live in extreme hot and dry conditions could fare well under a warming planet, the challenge will be for tropical agricultural and forest ecosystems to adapt to conditions that will likely surpass what they can currently tolerate," added coauthor Jamie Caldwell.

Still, it's not all about doom-saying and panic. The researchers stress that this work is intended to help nations prepare, not despair. Specifically, they point out that climate change will disproportionally impact the poorest countries in the world, who are already struggling to feed themselves.

Radical change then, may be necessary. Switching to heat tolerant and salt tolerant crops are two proposed routes, even as experts expect the world to cut its reliance on vulnerable cereals like wheat.

"Our study provides important policy implications," added Mora. "Imagine the political leverage that climate change could give to some countries if they gain the power to feed the rest of the world."

Food for thought, even while we all think about growing food.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

- follow Brian on Twitter @BS_ButNoBS