try this

CMakeLists.txt

@@ -43,11 +43,14 @@ if (NOT DEFINED MPILIB OR NOT ${MPILIB} STREQUAL "mpi-serial")
   find_package(MPI REQUIRED)
 endif()
 
-if (DEFINED ENV{ESMFMKFILE})
-  get_filename_component(ESMFLIB $ENV{ESMFMKFILE} DIRECTORY CACHE)
+if (DEFINED ENV{ESMF_ROOT})
+  list(APPEND CMAKE_MODULE_PATH $ENV{ESMF_ROOT}/cmake)
+else()
+  if (DEFINED ENV{ESMFMKFILE})
+    get_filename_component(ESMFLIB $ENV{ESMFMKFILE} DIRECTORY CACHE)
+    list(APPEND CMAKE_MODULE_PATH ${ESMFLIB}/../cmake)
+  endif()
 endif()
-list(APPEND CMAKE_MODULE_PATH ${ESMF_ROOT}/cmake)
-
 message("ESMF cmake is ${CMAKE_MODULE_PATH}")
 find_package(ESMF REQUIRED) 
 set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} ${ESMF_F90COMPILEPATHS}")