The phrase "and thereby decreasing" is correct and usable in written English.
It can be used to indicate that one action leads to a reduction or diminishment of something else.
Example: "The new policy was implemented to improve efficiency, and thereby decreasing operational costs."
Alternatives: "thus reducing" or "resulting in a decrease".
By reducing blood supply to the hubs, and thereby decreasing their activity, psilocybin allows a freer, less constrained state of awareness to emerge.
These medications are chemically absorbed into bone, decreasing osteoclast number and activity and thereby decreasing bone resorption.
Vasodilators act by relaxing smooth muscle in the walls of blood vessels, allowing small arteries to dilate and thereby decreasing total peripheral resistance.
The City further maintains that the review was reasonable because it was undertaken to determine if the communication plan's character limit on text messages was too low, and thereby decreasing the efficiency of the Department.
The presence of construction issues including thermal bridging, discrepancy in 'U' values and increases in air permeability contribute to increased heat loss and carbon emissions and thereby, decreasing energy and carbon efficiency.
The largest improvements would be made by design modifications adopting a novel energy conservation scenario by process integration and thereby decreasing the coal and water consumption and by decreasing the cold fresh air.
Visfatin mimics insulin functions and thereby decreases insulin resistance.
Incorporation of cholesterol sulfate stabilizes vesicles and thereby, decreases the elasticity.
I work at a hospital where several nurses practice therapies like healing touch and therapeutic touch, said to adjust a patient's energy field and thereby decrease pain and improve healing, although there is no significant evidence for this.
The cash savings attributed to tax avoidance help lower the default risk of a financially constrained firm and thereby decrease its future crash risk.
On Social Security the president has proposed changing the way that cost of living is calculated, to a formula that would produce lower estimates of what seniors need to live on and thereby decrease their benefits.
