How would you design a system to ensure data consistency across microservices in a distributed environment? Please discuss patterns you might employ and the challenges you expect to encounter.

``` You could utilize patterns like Event Sourcing and CQRS to achieve consistency. Event Sourcing keeps an immutable log of changes, allowing rebuilding of state from events, whereas CQRS separates read and write operations allowing for better scaling and performance. Challenges include handling network partitioning, eventual consistency, and failure management. ```